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Sample records for broad-spectrum antimicrobial chlorhexidine

  1. Community-Level Assessment of the Effects of the Broad-Spectrum Antimicrobial Chlorhexidine on the Outcome of River Microbial Biofilm Development▿

    OpenAIRE

    Lawrence, J R; Zhu, B.; Swerhone, G. D. W.; Topp, E.; Roy, J; L. I. Wassenaar; Rema, T.; Korber, D R

    2008-01-01

    Chlorhexidine is a common-use antibacterial agent found in a range of personal-care products. We used rotating annular reactors to cultivate river biofilms under the influence of chlorhexidine or its molar equivalent in nutrients. Studies of the degradation of [14C]chlorhexidine demonstrated that no mineralization of the compound occurred. During studies with 100 μg liter−1 chlorhexidine, significant changes were observed in the protozoan and micrometazoan populations, the algal and cyanobact...

  2. Broad-spectrum antimicrobial polycarbonate hydrogels with fast degradability.

    Science.gov (United States)

    Pascual, Ana; Tan, Jeremy P K; Yuen, Alex; Chan, Julian M W; Coady, Daniel J; Mecerreyes, David; Hedrick, James L; Yang, Yi Yan; Sardon, Haritz

    2015-04-13

    In this study, a new family of broad-spectrum antimicrobial polycarbonate hydrogels has been successfully synthesized and characterized. Tertiary amine-containing eight-membered monofunctional and difunctional cyclic carbonates were synthesized, and chemically cross-linked polycarbonate hydrogels were obtained by copolymerizing these monomers with a poly(ethylene glycol)-based bifunctional initiator via organocatalyzed ring-opening polymerization using 1,8-diazabicyclo[5.4.0]undec-7-ene catalyst. The gels were quaternized using methyl iodide to confer antimicrobial properties. Stable hydrogels were obtained only when the bifunctional monomer concentration was equal to or higher than 12 mol %. In vitro antimicrobial studies revealed that all quaternized hydrogels exhibited broad-spectrum antimicrobial activity against Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative), Pseudomonas aeruginosa (Gram-negative), and Candida albicans (fungus), while the antimicrobial activity of the nonquaternized hydrogels was negligible. Moreover, the gels showed fast degradation at room temperature (4-6 days), which makes them ideal candidates for wound healing and implantable biomaterials.

  3. Brevibacillus laterosporus, a Pathogen of Invertebrates and a Broad-Spectrum Antimicrobial Species

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    Luca Ruiu

    2013-09-01

    Full Text Available Brevibacillus laterosporus, a bacterium characterized by the production of a unique canoe-shaped lamellar body attached to one side of the spore, is a natural inhabitant of water, soil and insects. Its biopesticidal potential has been reported against insects in different orders including Coleoptera, Lepidoptera, Diptera and against nematodes and mollusks. In addition to its pathogenicity against invertebrates, different B. laterosporus strains show a broad-spectrum antimicrobial activity including activity against phytopathogenic bacteria and fungi. A wide variety of molecules, including proteins and antibiotics, have been associated with the observed pathogenicity and mode of action. Before being considered as a biological control agent against plant pathogens, the antifungal and antibacterial properties of certain B. laterosporus strains have found medical interest, associated with the production of antibiotics with therapeutic effects. The recent whole genome sequencing of this species revealed its potential to produce polyketides, nonribosomal peptides, and toxins. Another field of growing interest is the use of this bacterium for bioremediation of contaminated sites by exploiting its biodegradation properties. The aim of the present review is to gather and discuss all recent findings on this emerging entomopathogen, giving a wider picture of its complex and broad-spectrum biocontrol activity.

  4. L-carnitine esters as "soft", broad-spectrum antimicrobial amphiphiles.

    Science.gov (United States)

    Calvani, M; Critelli, L; Gallo, G; Giorgi, F; Gramiccioli, G; Santaniello, M; Scafetta, N; Tinti, M O; De Angelis, F

    1998-06-18

    A new class of antimicrobial, "soft", quaternary ammonium l-carnitine esters, of the type (CH3)3N+-CH2-CHOCO(R1)-CH2-COO(R2) Cl-, has been designed, with R1 and R2 being in general long-chain alkyl substituents. The series shows good activity against a wide range of bacteria, yeasts, and fungi. Lipophilicity has been measured by RP-HPLC method to give the logarithm of the experimental capacity factor (log k'), and a quantitative relationship has been determined between log k' and the theoretical partition coefficient (CLOGP); also, bond-dipole descriptors have been introduced into calculations by accounting for polar moieties present within the apolar cores of the molecules, giving a more refined calculated capacity factor (log k'calcd). Finally the latter has been related to the antimicrobial activity (MIC values). The proposed models are predictive for the best broad-spectrum antimicrobial compound within the series. PMID:9632355

  5. Expression of mouse beta defensin 2 in Escherichia coli and its broad-spectrum antimicrobial activity

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    Tianxiang Gong

    2011-09-01

    Full Text Available Mature mouse beta defensin 2 (mBD2 is a small cationic peptide with antimicrobial activity. Here we established a prokaryotic expression vector containing the cDNA of mature mBD2 fused with thioredoxin (TrxA, pET32a-mBD2. The vector was transformed into Escherichia Coli (E. coli Rosseta-gami (2 for expression fusion protein. Under the optimization of fermentation parameters: induce with 0.6 mM isopropylthiogalactoside (IPTG at 34ºC in 2×YT medium and harvest at 6 h postinduction, fusion protein TrxA-mBD2 was high expressed in the soluble fraction (>95%. After cleaved fusion protein by enterokinase, soluble mature mBD2 was achieved 6 mg/L with a volumetric productivity. Purified recombinant mBD2 demonstrated clear broad-spectrum antimicrobial activity for fungi, bacteria and virus. The MIC of antibacterial activity of against Staphylococcus aureus was 50 µg/ml. The MIC of against Candida albicans (C. albicans and Cryptococcus neoformans (C. neoformans was 12.5µg/ml and 25µg/ml, respectively. Also, the antimicrobial activity of mBD2 was effected by NaCl concentration. Additionally, mBD2 showed antiviral activity against influenza A virus (IAV, the protective rate for Madin-Darby canine kidney cells (MDCK was 93.86% at the mBD2 concentration of 100 µg/ml. These works might provide a foundation for the following research on the mBD2 as therapeutic agent for medical microbes.

  6. Development of a broad spectrum polymer-released antimicrobial coating for the prevention of resistant strain bacterial infections.

    Science.gov (United States)

    Sinclair, K D; Pham, T X; Farnsworth, R W; Williams, D L; Loc-Carrillo, C; Horne, L A; Ingebretsen, S H; Bloebaum, R D

    2012-10-01

    More than 400,000 primary hip and knee replacement surgeries are performed each year in the United States. From these procedures, approximately 0.5-3% will become infected and when considering revision surgeries, this rate has been found to increase significantly. Antibiotic-resistant bacterial infections are a growing problem in patient care. This in vitro research investigated the antimicrobial potential of the polymer released, broad spectrum, Cationic Steroidal Antimicrobial-13 (CSA-13) for challenges against 5 × 10(8) colony forming units (CFU) of methicillin-resistant Staphylococcus aureus (MRSA). It was hypothesized that a weight-to-weight (w/w) concentration of 18% CSA-13 in silicone would exhibit potent bactericidal potential when used as a controlled release device coating. When incorporated into a polymeric device coating, the 18% (w/w) broad-spectrum polymer released CSA-13 antimicrobial eliminated 5 × 10(8) CFU of MRSA within 8 h. In the future, these results will be utilized to develop a sheep model to assess CSA-13 for the prevention of perioperative device-related infections in vivo.

  7. Black cobra (Naja naja karachiensis) lysates exhibit broad-spectrum antimicrobial activities

    OpenAIRE

    Sagheer, Mehwish; Siddiqui, Ruqaiyyah; Iqbal, Junaid; Khan, Naveed Ahmed

    2014-01-01

    It is hypothesized that animals living in polluted environments possess antimicrobials to counter pathogenic microbes. The fact that snakes feed on germ-infested rodents suggests that they encounter pathogenic microbes and likely possess antimicrobials. The venom is used only to paralyze the rodent, but the ability of snakes to counter potential infections in the gut due to disease-ridden rodents requires robust action of the immune system against a broad range of pathogens. To test this hypo...

  8. A Broad-Spectrum Antimicrobial Activity of Bacillus subtilis RLID 12.1

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    Ramya Ramachandran

    2014-01-01

    Full Text Available In the present study, an attempt was made to biochemically characterize the antimicrobial substance from the soil isolate designated as RLID 12.1 and explore its potential applications in biocontrol of drug-resistant pathogens. The antimicrobial potential of the wild-type isolate belonging to the genus Bacillus was determined by the cut-well agar assay. The production of antimicrobial compound was recorded maximum at late exponential growth phase. The ultrafiltered concentrate was insensitive to organic solvents, metal salts, surfactants, and proteolytic and nonproteolytic enzymes. The concentrate was highly heat stable and active over a wide range of pH values. Partial purification, zymogram analysis, and TLC were performed to determine the preliminary biochemical nature. The molecular weight of the antimicrobial peptide was determined to be less than 2.5 kDa in 15% SDS-PAGE and in zymogram analysis against Streptococcus pyogenes. The N-terminal amino acid sequence by Edman degradation was partially determined to be T-P-P-Q-S-X-L-X-X-G, which shows very insignificant identity to other antimicrobial peptides from bacteria. The minimum inhibitory concentrations of dialysed and partially purified ion exchange fractions were determined against some selected gram-positive and gram-negative bacteria and some pathogenic yeasts. The presence of three important antimicrobial peptide biosynthesis genes ituc, fend, and bmyb was determined by PCR.

  9. Black cobra (Naja naja karachiensis) lysates exhibit broad-spectrum antimicrobial activities

    Science.gov (United States)

    Sagheer, Mehwish; Siddiqui, Ruqaiyyah; Iqbal, Junaid; Khan, Naveed Ahmed

    2014-01-01

    It is hypothesized that animals living in polluted environments possess antimicrobials to counter pathogenic microbes. The fact that snakes feed on germ-infested rodents suggests that they encounter pathogenic microbes and likely possess antimicrobials. The venom is used only to paralyze the rodent, but the ability of snakes to counter potential infections in the gut due to disease-ridden rodents requires robust action of the immune system against a broad range of pathogens. To test this hypothesis, crude lysates of different organs of Naja naja karachiensis (black cobra) were tested for antimicrobial properties. The antimicrobial activities of extracts were tested against selected bacterial pathogens (neuropathogenic Escherichia coli K1, methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Streptococcus pneumonia), protist (Acanthamoeba castellanii), and filamentous fungus (Fusarium solani). The findings revealed that plasma and various organ extracts of N. n. karachiensis exhibited antimicrobial activity against E. coli K1, MRSA, P. aeruginosa, S. pneumoniae, A. castellanii, and F. solani in a concentration-dependent manner. The results of this study are promising for the development of new antimicrobials. PMID:24625321

  10. A multidisciplinary antimicrobial stewardship programme safely decreases the duration of broad-spectrum antibiotic prescription in Singaporean adult renal patients.

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    Cai, Yiying; Shek, Pui Ying; Teo, Isabelle; Tang, Sarah S L; Lee, Winnie; Liew, Yi Xin; Chlebicki, Piotr; Kwa, Andrea L

    2016-01-01

    Patients with chronic kidney disease have increased risk of infections. Thus, physicians may favour prolonged broad-spectrum antibiotic use. Studies focused on antimicrobial stewardship programmes (ASPs) in renal patients are currently lacking. Here we describe the role of a multidisciplinary ASP and the impact of ASP interventions in renal patients. A multidisciplinary ASP was initiated at a tertiary hospital in Singapore. Patients prescribed broad-spectrum parenteral antibiotics were identified daily and were subjected to prospective review with immediate concurrent feedback. ASP data from January 2010 to December 2011 were analysed for all renal patients. Outcome measures included the duration and appropriateness of antibiotics, intervention acceptance rates, cost savings and safety outcomes. A total of 2084 antibiotic courses were reviewed, of which 24% were inappropriate, with meropenem most commonly prescribed inappropriately (31.0%). The commonest reasons for inappropriate use were wrong choice (51.0%) and wrong duration (21.4%). In total, 634 recommendations were made, with high acceptance rates (73.3%). Recommendations to discontinue antibiotics (33.4%) and to optimise doses (17.2%) comprised the bulk of ASP work. A mean reduction of -1.28 days of antibiotic use was observed among patients with interventions accepted versus those rejected (Pantibiotic use without compromising safety in renal patients. Continued effort is needed to produce a long-term impact on antibiotic prescription and resistance.

  11. Broad spectrum anti-microbial compounds producing bacteria from coast of Qingdao bays.

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    Khan, Muhammad Naseem; Li, Meng; Mirani, Zulfiqar Ali; Wang, Jingxue; Lin, Hong; Buzdar, Muhammad Aslam

    2015-03-01

    Anti-microbial resistance burden and hazard associated with chemical treatment of infections demanded for new anti-microbial natural products. Marine associated microorganisms are the enormous source of bioactive compounds. In this study we have isolated 272 marine bacteria among them 136 (50%) were antagonistic to at least one of the four pathogenic strains Listeria monocytogenes, Vibrio cholerae, E. coli and S. aureus. Only two strains exhibited antibacterial activity against all four test strains, which were identified by 16S rDNA sequencing as Bacillus sp. DK1-SA11 and Vibrio sp. DK6-SH8. Marine isolate DK1-SA11 has potential to resist boiling temperature and pH 2-12. Furthermore cell free extract (CFE) inhibited all test organisms including superbug MRSA and pathogenic yeast Candida albicans. Marine isolate Bacillus sp. DK1-SA11 could be a potential combatant for the battle of drugs and bugs. PMID:25730803

  12. Broad-Spectrum Antimicrobial Star Polycarbonates Functionalized with Mannose for Targeting Bacteria Residing inside Immune Cells.

    Science.gov (United States)

    Yang, Chuan; Krishnamurthy, Sangeetha; Liu, Jie; Liu, Shaoqiong; Lu, Xiaohua; Coady, Daniel J; Cheng, Wei; De Libero, Gennaro; Singhal, Amit; Hedrick, James L; Yang, Yi Yan

    2016-06-01

    In this study, a series of star-shaped polycarbonates are synthesized by metal-free organocatalytic ring-opening polymerization of benzyl chloride (BnCl) and mannose-functionalized cyclic carbonate monomers (MTC-BnCl and MTC-ipman) with heptakis-(2,3-di-O-acetyl)-β-cyclodextrin (DA-β-CD) as macroinitiator. The distributions and compositions of pendent benzyl chloride and protected mannose group (ipman) units are facilely modulated by varying the polymerization sequence and feed ratio of the monomers, allowing precise control over the molecular composition, and the resulting polymers have narrow molecular weight distribution. After deprotection of ipman groups and quaternization with various N,N-dimethylalkylamines, these star polymers with optimized compositions of cationic and mannose groups in block and random forms exhibit strong bactericidal activity and low hemolysis. Furthermore, the optimal mannose-functionalized polymer demonstrates mannose receptor-mediated intracellular bactericidal activity against BCG mycobacteria without inducing cytotoxicity on mammalian cells at the effective dose. Taken together, the materials designed in this study have potential use as antimicrobial agents against diseases such as tuberculosis, which is caused by intracellular bacteria.

  13. Characterization of a type-I crustin with broad-spectrum antimicrobial activity from red swamp crayfish Procambarus clarkii.

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    Liu, Ning; Zhang, Ran-Ran; Fan, Zhen-Xu; Zhao, Xiao-Fan; Wang, Xian-Wei; Wang, Jin-Xing

    2016-08-01

    Crustins are a family of antimicrobial peptides mainly identified in crustaceans and characterized by a whey acidic protein (WAP) domain and an additional glycine-, cysteine-, or proline-rich region. In this study, we identified and characterized PcCru, a new crustin isolated from red swamp crayfish Procambarus clarkii. The open reading frame of PcCru was 333 base pairs long and encoded a 110-residue polypeptide, which contained a signal peptide, a cysteine-rich region, and a WAP domain. The architecture and phylogenetic analysis suggested that PcCru was a new member of the type-I crustin family. PcCru was highly expressed in hemocytes and was significantly induced by viral and bacterial stimulations at both the translational and transcriptional levels. The titer of PcCru in circulating plasma was also increased considerably by bacterial challenge. Recombinant PcCru from both prokaryotic and eukaryotic expression systems were generated, and the proteins exhibited broad-spectrum antimicrobial activity. Furthermore, PcCru protected crayfish from infection by pathogenic bacteria Aeromonas hydrophila in vivo. This study provided new information emphasizing the important role of the crustin family in the crustacean antibacterial immune response. PMID:27021077

  14. Newly isolated Paenibacillus tyrfis sp. nov., from Malaysian tropical peat swamp soil with broad spectrum antimicrobial activity

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    Yoong Kit eAw

    2016-03-01

    Full Text Available Emergence of antimicrobial resistance coupled with the slowdown in discovery of new antimicrobial compounds points to serious consequences in human health. Therefore, scientists are looking for new antimicrobial compounds from unique and understudied ecosystem such as tropical peat swamp forests. Over the course of isolating antimicrobial producing bacteria from North Selangor tropical peat swamp forest, Malaysia, a Gram variable, rod shaped, endospore forming, facultative anaerobic novel strain MSt1T that exerts potent and broad spectrum antimicrobial activity was isolated. Phylogenetic analysis using 16S rRNA gene sequences showed that strain MSt1T belonged to the genus Paenibacillus with the highest similarity with Paenibacillus elgii SD17T (99.5%. Whole genome comparison between strain MSt1T with its closely related species using average nucleotide identity (ANI revealed that similarity between strain MSt1T with Paenibacillus elgii B69 (93.45% and Paenibacillus ehimensis A2 (90.42% was below the recommended threshold of 95%. Further analysis using in silico pairwise DDH also showed that similarity between strain MSt1T with P. elgii B69 (55.4% and P. ehimensis A2 (43.7% was below the recommended threshold of 70%. Strain MSt1T contained meso-diaminopilemic acid in the cell wall and MK-7 as the major menaquinone. The major fatty acids of strain MSt1T were anteiso-C15:0 (48.2% and C16:0 (29.0% whereas the polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, one unknown lipid, two unknown glycolipids and one unknown phospholipid. Total DNA G+C content of strain MSt1T was 51.5 mol%. Extract from strain MSt1T exerted strong antimicrobial activity against Escherichia coli ATCC 25922 (MIC = 1.5 µg/mL, MRSA ATCC 700699 (MIC = 25 µg/mL and Candida albicans IMR (MIC = 12.5 µg/mL. Partially purified active fraction exerted strong effect against Escherichia coli ATCC 25922 resulting in cell rupture

  15. De Novo Whole-Genome Sequence of Micromonospora carbonacea JXNU-1 with Broad-Spectrum Antimicrobial Activity, Isolated from Soil Samples

    OpenAIRE

    Jiang, Yun; Huang, Yun-hong; Long, Zhong-er

    2015-01-01

    Micromonospora carbonacea JXNU-1 is an actinomycete with broad-spectrum antimicrobial activity, isolated from soil samples from the farmland in the area of Yaohu Lake in Nanchang, China. Here, we report the whole-genome sequence of M. carbonacea JXNU-1.

  16. The impact of pricing and patent expiration on the demand for pharmaceuticals: An examination of the use of broad-spectrum antimicrobials

    OpenAIRE

    Kaier, Klaus

    2010-01-01

    The aim of the analysis was to determine whether demand in Germany for antibiotics is driven by prices that drop considerably when generic substitutes become available. A time-series approach was therefore carried out to explore price elasticities of demand for two different classes of broad-spectrum antimicrobials (fluoroquinolones and cephalosporins) using data on ambulatory antibiotics prescribed on the German statutory health insurance scheme and data on in-hospital antibiotic use in a Ge...

  17. Antimicrobial effect of alexidine and chlorhexidine against Enterococcus faecalis infection

    Institute of Scientific and Technical Information of China (English)

    Hyun-Shik Kim; Seok Woo Chang; Seung-Ho Baek; Seung Hyun Han; Yoon Lee; Qiang Zhu; Kee-Yeon Kum

    2013-01-01

    A previous study demonstrated that alexidine has greater affinity for the major virulence factors of bacteria than chlorhexidine. The aim of this study was to compare the antimicrobial activity of 1% alexidine with that of 2% chlorhexidine using Enterococcus faecalis.infected dentin blocks. Sixty bovine dentin blocks were prepared and randomly divided into six groups of 10 each. E. faecalis was inoculated on 60 dentin blocks using the Luppens apparatus for 24 h and then the dentin blocks were soaked in 2% chlorhexidine or 1% alexidine solutions for 5 and 10 min, respectively. Sterile saline was used as a control. The antimicrobial efficacy was assessed by counting the number of bacteria adhering to the dentin surface and observing the degradation of bacterial shape or membrane rupture under a scanning electron microscope. Significantly fewer bacteria were observed in the 2% chlorhexidine- or 1% alexidine-soaked groups than in the control group (P~O.05). However, there was no significant difference in the number of bacteria adhering to the dentinal surface between the two experimental groups or between the two soaking time groups (P>0.05). Ruptured or antiseptic-attached bacteria were more frequently observed in the lO-min-soaked chlorhexidine and alexidine groups than in the 5-min-soaked chlorhexidine and alexidine groups. In conclusion, lO-min soaking with 1% alexidine or 2% chlorhexidine can be effective against E. faecalis infection.

  18. Mussel-inspired synthesis of polydopamine-functionalized graphene oxide hydrogel as broad-spectrum antimicrobial material

    Science.gov (United States)

    Wang, Xinpeng; Liu, Zhiming; Zhong, Huiqing; Guo, Zhouyi; Yuan, Xiaochan

    2014-09-01

    Recently, three-dimensional GO-based hydrogels have attracted great attention due to the unique advantages. It is generally know that bacteria are everywhere and many of them could cause the diseases and threaten human health. However, developing new antibacterial materials with high-efficiency, low cost, broad-spectrum, and easy recycling is still a great challenge. Herein, inspired by mussel, we synthesized benzalkonium bromide/polydopamine/reduced graphene oxide hydrogel (BKB/PDA/rGOG). The as-prepared three-dimensional hydrogels were characterized by scanning eletron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy. The resultant hydrogels exhibited strong antibacterial effects to both Gram-negative and Gram-positive bacteria due to the synergistic effect of graphene oxide and benzalkonium bromide. In addition, the resultant hydrogels could be removed easily from the resolution, which was undoubtedly good news for industry application.

  19. Antimicrobial activity of selected Iranian medicinal plants against a broad spectrum of pathogenic and drug multiresistant micro-organisms.

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    Abedini, A; Roumy, V; Mahieux, S; Gohari, A; Farimani, M M; Rivière, C; Samaillie, J; Sahpaz, S; Bailleul, F; Neut, C; Hennebelle, T

    2014-10-01

    The antimicrobial activities of 44 methanolic extracts from different parts of Iranian indigenous plant species used in traditional medicines of Iran were tested against a panel of 35 pathogenic and multiresistant bacteria and 1 yeast. The antimicrobial efficacy was determined using Müller-Hinton agar in Petri dishes seeded by a multiple inoculator and minimal inhibition concentration (MIC) method. The 21 most active extracts (MIC < 0·3 mg ml(-1) for one or several micro-organisms) were submitted to a more refined measurement. The best antibacterial activity was obtained by 10 plants. Microdilution assays allowed to determinate the MIC and MBC of the 21 most active extracts. The lowest achieved MIC value was 78 μg ml(-1), with 4 extracts. This work confirms the antimicrobial activity of assayed plants and suggests further examination to identify the chemical structure of their antimicrobial compounds. Significance and impact of the study: This study describes the antimicrobial screening of Iranian plant extracts chosen according to traditional practice against 36 microbial strains, from reference culture collections or recent clinical isolates, and enables to select 4 candidates for further chemical characterization and biological assessment: Dorema ammoniacum, Ferula assa-foetida, Ferulago contracta (seeds) and Perovskia abrotanoides (aerial parts). This may be useful in the development of potential antimicrobial agents, from easily harvested and highly sustainable plant parts. Moreover, the weak extent of cross-resistance between plant extracts and antibiotics warrants further research and may promote a strategy based on less potent but time-trained products. PMID:24888993

  20. Draft Genome Sequence of Brevibacillus brevis DZQ7, a Plant Growth-Promoting Rhizobacterium with Broad-Spectrum Antimicrobial Activity

    OpenAIRE

    Hou, Qihui; Wang, Chengqiang; Hou, Xiaoyang; Xia, Zhilin; Ye, Jiangping; Liu, Kai; Liu, Hu; Wang, Jun; Guo, Haimeng; Yu, Xiaoning; Yang, Yanan; Du, Binghai; Ding, Yanqin

    2015-01-01

    Brevibacillus brevis DZQ7 is a plant growth-promoting rhizobacterium (PGPR) isolated from tobacco rhizosphere. Here, we report the draft genome sequence of B. brevis DZQ7. Several functional genes related to antimicrobial activity were identified in the genome.

  1. Draft Genome Sequence of Brevibacillus brevis DZQ7, a Plant Growth-Promoting Rhizobacterium with Broad-Spectrum Antimicrobial Activity.

    Science.gov (United States)

    Hou, Qihui; Wang, Chengqiang; Hou, Xiaoyang; Xia, Zhilin; Ye, Jiangping; Liu, Kai; Liu, Hu; Wang, Jun; Guo, Haimeng; Yu, Xiaoning; Yang, Yanan; Du, Binghai; Ding, Yanqin

    2015-01-01

    Brevibacillus brevis DZQ7 is a plant growth-promoting rhizobacterium (PGPR) isolated from tobacco rhizosphere. Here, we report the draft genome sequence of B. brevis DZQ7. Several functional genes related to antimicrobial activity were identified in the genome. PMID:26294619

  2. Comparative Evaluation of the Antimicrobial Properties of Glass Ionomer Cements with and without Chlorhexidine Gluconate

    Science.gov (United States)

    Jampanapalli, Sharada Reddy; Konda, Suhasini; Inguva, Hema Chandrika; Chimata, Vamsi Krishna

    2016-01-01

    ABSTRACT Background: Chlorhexidine gluconate is a widely used antimicrobial agent. Adding chlorhexidine and quaternary ammonium compounds to filling materials, such as composite resins, acrylic resins, and glass ionomer cements increases the antibacterial property of restorative materials. This study includes antibacterial property of glass ionomer restorative cements with chlorhexidine gluconate. Aim: The primary objective of our study was to compare the antimicrobial properties of two commercially available glass ionomer cements with and without chlorhexidine gluconate on strains of mutans streptococci. Materials and methods: Two glass ionomers (Fuji II Conventional and Fuji IX) were used. Chlorhexidine gluconate was mixed with glass ionomer cements, and antimicrobial properties against mutans streptococci were assessed by agar diffusion. The tested bacterial strain was inhibited and the antimicrobial properties decreased with time. Results: The highest amount of antimicrobial activity with mean inhibitory zone was found in Fuji II with chlorhexidine gluconate followed by Fuji IX with chlorhexidine gluconate, Fuji II without chlorhexidine gluconate, and Fuji IX without chlorhexidine gluconate. Conclusion: The results of the study confirmed that the addition of 5% chlorhexidine gluconate to Fuji II and Fuji IX glass ionomer cements resulted in a restorative material that had increased antimicrobial properties over the conventional glass ionomer cements alone for Streptococcus mutans. How to cite this article: Yadiki JV, Jampanapalli SR , Konda S, Inguva HC, Chimata VK. Comparative Evaluation of the Antimicrobial Properties of Glass Ionomer Cements with and without Chlorhexidine Gluconate. Int J Clin Pediatr Dent 2016;9(2):99-103. PMID:27365927

  3. The freshwater sponge Ephydatia fluviatilis harbours diverse Pseudomonas species (Gammaproteobacteria, Pseudomonadales) with broad-spectrum antimicrobial activity.

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    Keller-Costa, Tina; Jousset, Alexandre; van Overbeek, Leo; van Elsas, Jan Dirk; Costa, Rodrigo

    2014-01-01

    Bacteria are believed to play an important role in the fitness and biochemistry of sponges (Porifera). Pseudomonas species (Gammaproteobacteria, Pseudomonadales) are capable of colonizing a broad range of eukaryotic hosts, but knowledge of their diversity and function in freshwater invertebrates is rudimentary. We assessed the diversity, structure and antimicrobial activities of Pseudomonas spp. in the freshwater sponge Ephydatia fluviatilis. Polymerase Chain Reaction--Denaturing Gradient Gel Electrophoresis (PCR-DGGE) fingerprints of the global regulator gene gacA revealed distinct structures between sponge-associated and free-living Pseudomonas communities, unveiling previously unsuspected diversity of these assemblages in freshwater. Community structures varied across E. fluviatilis specimens, yet specific gacA phylotypes could be detected by PCR-DGGE in almost all sponge individuals sampled over two consecutive years. By means of whole-genome fingerprinting, 39 distinct genotypes were found within 90 fluorescent Pseudomonas isolates retrieved from E. fluviatilis. High frequency of in vitro antibacterial (49%), antiprotozoan (35%) and anti-oomycetal (32%) activities was found among these isolates, contrasting less-pronounced basidiomycetal (17%) and ascomycetal (8%) antagonism. Culture extracts of highly predation-resistant isolates rapidly caused complete immobility or lysis of cells of the protozoan Colpoda steinii. Isolates tentatively identified as P. jessenii, P. protegens and P. oryzihabitans showed conspicuous inhibitory traits and correspondence with dominant sponge-associated phylotypes registered by cultivation-independent analysis. Our findings suggest that E. fluviatilis hosts both transient and persistent Pseudomonas symbionts displaying antimicrobial activities of potential ecological and biotechnological value. PMID:24533086

  4. Novel Broad-Spectrum Antimicrobial Photoinactivation of In Situ Oral Biofilms by Visible Light plus Water-Filtered Infrared A.

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    Karygianni, L; Ruf, S; Follo, M; Hellwig, E; Bucher, M; Anderson, A C; Vach, K; Al-Ahmad, A

    2014-12-01

    Antimicrobial photodynamic therapy (APDT) has gained increased attention as an alternative treatment approach in various medical fields. However, the effect of APDT using visible light plus water-filtered infrared A (VIS + wIRA) on oral biofilms remains unexplored. For this purpose, initial and mature oral biofilms were obtained in situ; six healthy subjects wore individual upper jaw acrylic devices with bovine enamel slabs attached to their proximal sites for 2 h or 3 days. The biofilms were incubated with 100 μg ml(-1) toluidine blue O (TB) or chlorin e6 (Ce6) and irradiated with VIS + wIRA with an energy density of 200 mW cm(-2) for 5 min. After cultivation, the CFU of half of the treated biofilm samples were quantified, whereas following live/dead staining, the other half of the samples were monitored by confocal laser scanning microscopy (CLSM). TB- and Ce6-mediated APDT yielded a significant decrease of up to 3.8 and 5.7 log10 CFU for initial and mature oral biofilms, respectively. Quantification of the stained photoinactivated microorganisms confirmed these results. Overall, CLSM revealed the diffusion of the tested photosensitizers into the deepest biofilm layers after exposure to APDT. In particular, Ce6-aided APDT presented elevated permeability and higher effectiveness in eradicating 89.62% of biofilm bacteria compared to TB-aided APDT (82.25%) after 3 days. In conclusion, antimicrobial photoinactivation using VIS + wIRA proved highly potent in eradicating oral biofilms. Since APDT excludes the development of microbial resistance, it could supplement the pharmaceutical treatment of periodontitis or peri-implantitis.

  5. Broad-Spectrum Antimicrobial Effects of Photocatalysis Using Titanium Dioxide Nanoparticles Are Strongly Potentiated by Addition of Potassium Iodide.

    Science.gov (United States)

    Huang, Ying-Ying; Choi, Hwanjun; Kushida, Yu; Bhayana, Brijesh; Wang, Yuguang; Hamblin, Michael R

    2016-09-01

    Photocatalysis describes the excitation of titanium dioxide nanoparticles (a wide-band gap semiconductor) by UVA light to produce reactive oxygen species (ROS) that can destroy many organic molecules. This photocatalysis process is used for environmental remediation, while antimicrobial photocatalysis can kill many classes of microorganisms and can be used to sterilize water and surfaces and possibly to treat infections. Here we show that addition of the nontoxic inorganic salt potassium iodide to TiO2 (P25) excited by UVA potentiated the killing of Gram-positive bacteria, Gram-negative bacteria, and fungi by up to 6 logs. The microbial killing depended on the concentration of TiO2, the fluence of UVA light, and the concentration of KI (the best effect was at 100 mM). There was formation of long-lived antimicrobial species (probably hypoiodite and iodine) in the reaction mixture (detected by adding bacteria after light), but short-lived antibacterial reactive species (bacteria present during light) produced more killing. Fluorescent probes for ROS (hydroxyl radical and singlet oxygen) were quenched by iodide. Tri-iodide (which has a peak at 350 nm and a blue product with starch) was produced by TiO2-UVA-KI but was much reduced when methicillin-resistant Staphylococcus aureus (MRSA) cells were also present. The model tyrosine substrate N-acetyl tyrosine ethyl ester was iodinated in a light dose-dependent manner. We conclude that UVA-excited TiO2 in the presence of iodide produces reactive iodine intermediates during illumination that kill microbial cells and long-lived oxidized iodine products that kill after light has ended. PMID:27381399

  6. Broad-Spectrum Antimicrobial Effects of Photocatalysis Using Titanium Dioxide Nanoparticles Are Strongly Potentiated by Addition of Potassium Iodide.

    Science.gov (United States)

    Huang, Ying-Ying; Choi, Hwanjun; Kushida, Yu; Bhayana, Brijesh; Wang, Yuguang; Hamblin, Michael R

    2016-09-01

    Photocatalysis describes the excitation of titanium dioxide nanoparticles (a wide-band gap semiconductor) by UVA light to produce reactive oxygen species (ROS) that can destroy many organic molecules. This photocatalysis process is used for environmental remediation, while antimicrobial photocatalysis can kill many classes of microorganisms and can be used to sterilize water and surfaces and possibly to treat infections. Here we show that addition of the nontoxic inorganic salt potassium iodide to TiO2 (P25) excited by UVA potentiated the killing of Gram-positive bacteria, Gram-negative bacteria, and fungi by up to 6 logs. The microbial killing depended on the concentration of TiO2, the fluence of UVA light, and the concentration of KI (the best effect was at 100 mM). There was formation of long-lived antimicrobial species (probably hypoiodite and iodine) in the reaction mixture (detected by adding bacteria after light), but short-lived antibacterial reactive species (bacteria present during light) produced more killing. Fluorescent probes for ROS (hydroxyl radical and singlet oxygen) were quenched by iodide. Tri-iodide (which has a peak at 350 nm and a blue product with starch) was produced by TiO2-UVA-KI but was much reduced when methicillin-resistant Staphylococcus aureus (MRSA) cells were also present. The model tyrosine substrate N-acetyl tyrosine ethyl ester was iodinated in a light dose-dependent manner. We conclude that UVA-excited TiO2 in the presence of iodide produces reactive iodine intermediates during illumination that kill microbial cells and long-lived oxidized iodine products that kill after light has ended.

  7. Graphene oxide exhibits broad-spectrum antimicrobial activity against bacterial phytopathogens and fungal conidia by intertwining and membrane perturbation

    Science.gov (United States)

    Chen, Juanni; Peng, Hui; Wang, Xiuping; Shao, Feng; Yuan, Zhaodong; Han, Heyou

    2014-01-01

    To understand the interaction mechanism between graphene oxide (GO) and typical phytopathogens, a particular investigation was conducted about the antimicrobial activity of GO against two bacterial pathogens (P. syringae and X. campestris pv. undulosa) and two fungal pathogens (F. graminearum and F. oxysporum). The results showed that GO had a powerful effect on the reproduction of all four pathogens (killed nearly 90% of the bacteria and repressed 80% macroconidia germination along with partial cell swelling and lysis at 500 μg mL-1). A mutual mechanism is proposed in this work that GO intertwinds the bacteria and fungal spores with a wide range of aggregated graphene oxide sheets, resulting in the local perturbation of their cell membrane and inducing the decrease of the bacterial membrane potential and the leakage of electrolytes of fungal spores. It is likely that GO interacts with the pathogens by mechanically wrapping and locally damaging the cell membrane and finally causing cell lysis, which may be one of the major toxicity actions of GO against phytopathogens. The antibacterial mode proposed in this study suggests that the GO may possess antibacterial activity against more multi-resistant bacterial and fungal phytopathogens, and provides useful information about the application of GO in resisting crop diseases.To understand the interaction mechanism between graphene oxide (GO) and typical phytopathogens, a particular investigation was conducted about the antimicrobial activity of GO against two bacterial pathogens (P. syringae and X. campestris pv. undulosa) and two fungal pathogens (F. graminearum and F. oxysporum). The results showed that GO had a powerful effect on the reproduction of all four pathogens (killed nearly 90% of the bacteria and repressed 80% macroconidia germination along with partial cell swelling and lysis at 500 μg mL-1). A mutual mechanism is proposed in this work that GO intertwinds the bacteria and fungal spores with a wide range

  8. Induced Sporicidal Activity of Chlorhexidine against Clostridium difficile Spores under Altered Physical and Chemical Conditions

    OpenAIRE

    Nerandzic, Michelle M.; Donskey, Curtis J.

    2015-01-01

    Background Chlorhexidine is a broad-spectrum antimicrobial commonly used to disinfect the skin of patients to reduce the risk of healthcare-associated infections. Because chlorhexidine is not sporicidal, it is not anticipated that it would have an impact on skin contamination with Clostridium difficile, the most important cause of healthcare-associated diarrhea. However, although chlorhexidine is not sporicidal as it is used in healthcare settings, it has been reported to kill spores of Bacil...

  9. In vitro susceptibility of Streptococcus mutans to chlorhexidine and six other antimicrobial agents.

    OpenAIRE

    Järvinen, H; Tenovuo, J; Huovinen, P

    1993-01-01

    The susceptibility of Streptococcus mutans to chlorhexidine and to six commonly used, systemic antibacterial agents (amoxicillin, cefuroxime, penicillin, sulfamethoxazole-trimethoprim, tetracycline, and erythromycin) was studied for 424 clinical isolates from 116 children and students. The MIC of chlorhexidine for all isolates was < or = 1 micrograms/ml. No resistance to the other antimicrobial agents was detected. Although widely exposed to various antimicrobial agents, S. mutans has remaine...

  10. Antimicrobial activity of calcium hydroxide and chlorhexidine on intratubular Candida albicans

    Institute of Scientific and Technical Information of China (English)

    Ronan Jacques Rezende Delgado; Thaís Helena Gasparoto; Carla Renata Sipert; Claudia Ramos Pinheiro; Ivaldo Gomes de Moraes; Roberto Brandāo Garcia; Marco Antonio Hungaro Duarte; Clóvis Monteiro Bramante; Sérgio Aparecido Torres; Gustavo Pompermaier Garlet; Ana Paula Campanelli; Norberti Bernardineli

    2013-01-01

    This study investigated the efficacy of calcium hydroxide and chlorhexidine gel for the elimination of intratubular Candida albicans (C. albicans). Human single-rooted teeth contaminated with C. albicans were treated with calcium hydroxide, 2% chlorhexidine gel, calcium hydroxide plus 2% chlorhexidine gel, or saline (0.9% sodium chloride) as a positive control. The samples obtained at depths of 0-100 and 100-200 μm from the root canal system were analyzed for C. albicans load by counting the number of colony forming units and for the percentage of viable C. albicans using fluorescence microscopy. First, the antimicrobial activity of calcium hydroxide and the 2% chlorhexidine gel was evaluated by counting the number of colony forming units. After 14 days of intracanal medication, there was a significant decrease in the number of C. albicanscolony forming units at a depth of 0-100 lzm with chlorhexidine treatment either with or without calcium hydroxide compared with the calcium hydroxide only treatment. However, there were no differences in the number of colony forming units at the 100-200 μm depth for any of the medications investigated. C. albicans viability was also evaluated by vital staining techniques and fluorescence microscopy analysis. Antifungal activity against C. albicans significantly increased at both depths in the chlorhexidine groups with and without calcium hydroxide compared with the groups treated with calcium hydroxide only. Treatments with only chlorhexidine or chlorhexidine in combination with calcium hydroxide were effective for elimination of C. albicans.

  11. Antimicrobial interactions (synergy) of teicoplanin with two broad-spectrum drugs (cefotaxime, ofloxacin) tested against gram-positive isolates from Germany and the United States.

    Science.gov (United States)

    Jones, R N; Marshall, S A; Grimm, H

    1997-10-01

    Teicoplanin, a glycopeptide, has been widely used in some nations alone and in empiric therapy combinations to address infections caused by Gram-positive cocci. However, glycopeptide resistance and the increasing incidence of oxacillin-resistant staphylococci have compromised contemporary chemotherapy. In this study, teicoplanin was tested in combinations with ampicillin, cefotaxime with and without desacetylcefotaxime, and ofloxacin against 151 Gram-positive cocci to assess the potential for enhanced action. The strains included recent isolates from the United States and Germany having well-characterized resistance mechanisms (oxacillin-resistant staphylococci, vancomycin-resistant enterococci), each tested by NCCLS methods, checkerboard synergy tests, and kill-curves. Teicoplanin alone was active (MIC90s, 0.25-2 micrograms/mL) against all species except vanA enterococci. Drug interactions of teicoplanin with beta-lactams revealed synergy and partial synergy versus oxacillin-resistant Staphylococcus spp. (67-100%) and vancomycin-resistant enterococci (70-100%), many at clinically achievable drug concentrations. However, confirming kill-curve experiments showed static action and no significant bactericidal effect. Combinations of ofloxacin with teicoplanin or cefotaxime plus desacetylcefotaxime showed a dominant additive and indifferent interaction. Teicoplanin continues to be a viable alternative to vancomycin, especially in combination therapy with selected broad-spectrum cephalosporins or fluoroquinolones. Many emerging pathogens that test resistant to individual drugs appear to be inhibited by tested combinations, extending their potential clinical utility.

  12. Antimicrobial peptides effectively kill a broad spectrum of Listeria monocytogenes and Staphylococcus aureus strains independently of origin, sub-type, or virulence factor expression

    DEFF Research Database (Denmark)

    Gottlieb, Caroline Trebbien; Thomsen, L.E.; Ingmer, H.;

    2008-01-01

    Background Host defense peptides (HDPs), or antimicrobial peptides (AMPs), are important components of the innate immune system that bacterial pathogens must overcome to establish an infection and HDPs have been suggested as novel antimicrobial therapeutics in treatment of infectious diseases......-type, and phenotypic behavior. Strains within each species were equally sensitive to HDPs and oxidative stress representing important components of the innate immune defense system. Four non-human peptides (protamine, plectasin, novicidin, and novispirin G10) were similar in activity profile (MIC value spectrum...

  13. Phylloseptin-PBa—A Novel Broad-Spectrum Antimicrobial Peptide from the Skin Secretion of the Peruvian Purple-Sided Leaf Frog (Phyllomedusa Baltea Which Exhibits Cancer Cell Cytotoxicity

    Directory of Open Access Journals (Sweden)

    Yuantai Wan

    2015-12-01

    Full Text Available Antimicrobial peptides from amphibian skin secretion display remarkable broad-spectrum antimicrobial activity and are thus promising for the discovery of new antibiotics. In this study, we report a novel peptide belonging to the phylloseptin family of antimicrobial peptides, from the skin secretion of the purple-sided leaf frog, Phyllomedusa baltea, which was named Phylloseptin-PBa. Degenerate primers complementary to putative signal peptide sites of frog skin peptide precursor-encoding cDNAs were designed to interrogate a skin secretion-derived cDNA library from this frog. Subsequently, the peptide was isolated and identified using reverse phase HPLC and MS/MS fragmentation. The synthetic replicate was demonstrated to have activity against S. aureus, E. coli and C. albicans at concentrations of 8, 128 and 8 mg/L, respectively. In addition, it exhibited anti-proliferative activity against the human cancer cell lines, H460, PC3 and U251MG, but was less active against a normal human cell line (HMEC. Furthermore, a haemolysis assay was performed to assess mammalian cell cytotoxicity of Phylloseptin-PBa. This peptide contained a large proportion of α-helical domain, which may explain its antimicrobial and anticancer activities.

  14. Essential Oils and Non-volatile Compounds Derived from Chamaecyparis obtusa: Broad Spectrum Antimicrobial Activity against Infectious Bacteria and MDR(multidrug resistant) Strains.

    Science.gov (United States)

    Bae, Min-Suk; Park, Dae-Hun; Choi, Chul-Yung; Kim, Gye-Yeop; Yoo, Jin-Cheol; Cho, Seung-Sik

    2016-05-01

    The aim of this study was to evaluate the antibacterial activity of essential oil from Chamaecyparis obtusa against general infectious microbes and drug resistant strains of clinical origin. The results indicate that both essential oil and non-volatile residue have broad inhibitory activity against test strains. Essential oil and non-volatile residues showed antimicrobial activity not only against general infectious bacteria, but also against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) strains. PMID:27319153

  15. Broad-spectrum antimicrobial photocatalysis mediated by titanium dioxide and UVA is potentiated by addition of bromide ion via formation of hypobromite.

    Science.gov (United States)

    Wu, Ximing; Huang, Ying-Ying; Kushida, Yu; Bhayana, Brijesh; Hamblin, Michael R

    2016-06-01

    Antimicrobial photocatalysis involves the UVA excitation of titanium dioxide (TiO2) nanoparticles (particularly the anatase form) to produce reactive oxygen species (ROS) that kill microbial cells. For the first time we report that the addition of sodium bromide to photoactivated TiO2 (P25) potentiates the killing of Gram-positive, Gram-negative bacteria and fungi by up to three logs. The potentiation increased with increasing bromide concentration in the range of 0-10mM. The mechanism of potentiation is probably due to generation of both short and long-lived oxidized bromine species including hypobromite as shown by the following observations. There is some antimicrobial activity remaining in solution after switching off the light, that lasts for 30min but not 2h, and oxidizes 3,3',5,5'-tetramethylbenzidine. N-acetyl tyrosine ethyl ester was brominated in a light dose-dependent manner, however no bromine or tribromide ion could be detected by spectrophotometry or LC-MS. The mechanism appears to have elements in common with the antimicrobial system (myeloperoxidase+hydrogen peroxide+bromide). PMID:27012419

  16. Broad-spectrum antimicrobial photocatalysis mediated by titanium dioxide and UVA is potentiated by addition of bromide ion via formation of hypobromite.

    Science.gov (United States)

    Wu, Ximing; Huang, Ying-Ying; Kushida, Yu; Bhayana, Brijesh; Hamblin, Michael R

    2016-06-01

    Antimicrobial photocatalysis involves the UVA excitation of titanium dioxide (TiO2) nanoparticles (particularly the anatase form) to produce reactive oxygen species (ROS) that kill microbial cells. For the first time we report that the addition of sodium bromide to photoactivated TiO2 (P25) potentiates the killing of Gram-positive, Gram-negative bacteria and fungi by up to three logs. The potentiation increased with increasing bromide concentration in the range of 0-10mM. The mechanism of potentiation is probably due to generation of both short and long-lived oxidized bromine species including hypobromite as shown by the following observations. There is some antimicrobial activity remaining in solution after switching off the light, that lasts for 30min but not 2h, and oxidizes 3,3',5,5'-tetramethylbenzidine. N-acetyl tyrosine ethyl ester was brominated in a light dose-dependent manner, however no bromine or tribromide ion could be detected by spectrophotometry or LC-MS. The mechanism appears to have elements in common with the antimicrobial system (myeloperoxidase+hydrogen peroxide+bromide).

  17. Chlorhexidine as a root canal irrigant: Antimicrobial and scanning electron microscopic evaluation

    OpenAIRE

    Živković Slavoljub; Pavlović Violeta

    2010-01-01

    Introduction. Selection of irrigant is very important for longterm success of root canal therapy. Objective. This study was undertaken to evaluate the antimicrobial effects of 2% chlorhexidine digluconate solution (CHX) against five selected microorganisms and to evaluate its efficacy in root canal cleaning. Methods. In this study, by agar diffusion test, were evaluated antimicrobial effects of three root canal irrigants: 5.25% NaOCl, 2.5% NaOCl and 2% CHX. The microorganisms tested in ...

  18. Anti-lipopolysaccharide factor in Litopenaeus vannamei (LvALF): a broad spectrum antimicrobial peptide essential for shrimp immunity against bacterial and fungal infection.

    Science.gov (United States)

    de la Vega, Enrique; O'Leary, Nuala A; Shockey, Jessica E; Robalino, Javier; Payne, Caroline; Browdy, Craig L; Warr, Gregory W; Gross, Paul S

    2008-04-01

    Antimicrobial peptides are an essential component of the innate immune system of most organisms. Expressed sequence tag analysis from various shrimp (Litopenaeus vannamei) tissues revealed transcripts corresponding to two distinct sequences (LvALF1 and LvALF2) with strong sequence similarity to anti-lipopolysaccharide factor (ALF), an antimicrobial peptide originally isolated from the horseshoe crab Limulus polyphemus. Full-length clones contained a 528bp transcript with a predicted open reading frame coding for 120 amino acids in LvALF1, and a 623bp transcript with a predicted open reading frame coding for 93 amino acids in LvALF2. A reverse genetic approach was implemented to study the in vivo role of LvALF1 in protecting shrimp from bacterial, fungal and viral infections. Injection of double-stranded RNA (dsRNA) corresponding to the LvALF1 message resulted in a significant reduction of LvALF1 mRNA transcript abundance as determined by qPCR. Following knockdown, shrimp were challenged with low pathogenic doses of Vibrio penaeicida, Fusarium oxysporum or white spot syndrome virus (WSSV) and the resulting mortality curves were compared with controls. A significant increase of mortality in the LvALF1 knockdown shrimp was observed in the V. penaeicida and F. oxysporum infections when compared to controls, showing that this gene has a role in protecting shrimp from both bacterial and fungal infections. In contrast, LvALF1 dsRNA activated the sequence-independent innate anti-viral immune response giving increased protection from WSSV infection.

  19. Effect of addition of 2% chlorhexidine or 10% doxycycline on antimicrobial activity of biodentine

    Directory of Open Access Journals (Sweden)

    Vineeta Nikhil

    2014-01-01

    Full Text Available Aim: The purpose of this in vitro study was to determine whether the addition of 2% chlorhexidine gluconate or 10% doxycycline would enhance the antimicrobial activity of Biodentine against Staphylococcus aureus (ATCC-25923, Enterococcus faecalis (ATCC-29212, Candida albicans (ATCC-90028, and Streptococcus mutans (MTCC-497. Materials and Methods: Three wells of 4 mm diameter and 4 mm depth on each plate were prepared on the agar medium with standardized suspensions of each microorganism. Biodentine powder mixed with 2% chlorhexidine (0.06 g or 10% doxycycline (0.30 g in its liquid or liquid alone was placed to fill each well. Plates were incubated at 37°C as required for microbial growth. A blinded, independent observer measured zones of inhibition. The data were analyzed using independent "t" test to compare the differences among the three cement preparations for different micro-organisms. Results: All Biodentine samples inhibited microbial growth. The highest mean diameters of zone of inhibition for all the micro-organisms were found around Biodentine/chlorhexidine (13.417 followed by Biodentine alone (12.236 and Biodentine/doxycycline (11.25. Conclusion: In conclusion, adding 2% chlorhexidine gluconate in liquid of Biodentine enhanced the antimicrobial activity of Biodentine against all the tested micro-organisms except Candida albicans, while addition of 10% doxycycline decreased the antimicrobial activity of Biodentine. The differences were significant statistically (P < 0.05.

  20. Synergistic Antimicrobial Action of Chlorhexidine and Ozone in Endodontic Treatment

    OpenAIRE

    Rita Noites; Cidália Pina-Vaz; Rita Rocha; Manuel Fontes Carvalho; Acácio Gonçalves; Irene Pina-vaz

    2014-01-01

    Objectives. The aim of this study was to determine whether irrigation with sodium hypochlorite, chlorhexidine, and ozone gas, alone or in combination, were effective against Enterococcus faecalis and Candida albicans; these are microorganisms frequently isolated from teeth with periapical lesions resistant to endodontic treatment. Material and Methods. 220 single root teeth, recently extracted, were inoculated with Candida albicans and Enterococcus faecalis. The formulations tested were sodiu...

  1. Antimicrobial Activity of Peganum Harmala L. on Streptococcus mutans Compared to 0.2% Chlorhexidine

    Science.gov (United States)

    Motamedifar, Mohammad; Khosropanah, Hengameh; Dabiri, Shima

    2016-01-01

    Statement of the Problem Dental caries is one the most prevalent diseases that affects humans throughout their lives. Streptococcus mutans (S. mutans) is recognized as the most important microorganism during tooth cariogenicity. Reducing this germ in oral cavity can reduce the rate of tooth decays in humans. Purpose The present study compared the antimicrobial activity of ethanolic extract of Peganum harmala L. seeds and 0.2% chlorhexidine on S. mutans. Materials and Method Agar diffusion technique and micro broth dilution method were employed to test the antimicrobial effects of these two agents on S. mutans. Moreover, the cytotoxicity of ethanolic extract of P. harmala was studied on Vero cells by MTT (thiazolyl blue tetrazolium dye) colorimetric method. The data were analyzed with descriptive methods. Results Concentrations of 50, 25, and 12.5 mg/mL of the extract made inhibition zones of bacterial growth around the wells; but, lower concentrations could not inhibit the growth of S. mutans. Besides, the antimicrobial effect of 0.2% chlorhexidine was more than 50 mg/mL of the extract. Minimum inhibitory concentration (MIC) of the extract on S. mutans was 1.83±0.6 mg/mL and minimum bactericidal concentration (MBC) was 4.3±1 mg/mL. The MIC and MBC for 0.2% chlorhexidine were reported to be 0.19 mg/mL, and 0.78 mg/mL, respectively. The extract concentrations more than 0.5 mg/mL were toxic and caused more than 50% Vero cell death. Conclusion Despite the remarkable antimicrobial effects of high concentrations of P. harmala on S. mutans, high cell toxicity of this plant would restrict its in vivo therapeutic use. PMID:27602397

  2. Chlorhexidine as a root canal irrigant: Antimicrobial and scanning electron microscopic evaluation

    Directory of Open Access Journals (Sweden)

    Živković Slavoljub

    2010-01-01

    Full Text Available Introduction. Selection of irrigant is very important for longterm success of root canal therapy. Objective. This study was undertaken to evaluate the antimicrobial effects of 2% chlorhexidine digluconate solution (CHX against five selected microorganisms and to evaluate its efficacy in root canal cleaning. Methods. In this study, by agar diffusion test, were evaluated antimicrobial effects of three root canal irrigants: 5.25% NaOCl, 2.5% NaOCl and 2% CHX. The microorganisms tested in this study were Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, Escherichia coli and Candida albicans. A scanning electron microscope was used to evaluate root canal cleaning ability of 5.25% NaOCl, 2.5% NaOCl, 2% CHX and 15% EDTA. Twelve extracted single-root human teeth were divided into four groups depending on the irrigant used during instrumentation. Mechanical preparation was performed with Step back technique and K files. Data were analyzed statistically by Student’s t-test. Results 5.25% NaOCl was the most effective against all tested microorganisms. 2.5% NaOCl and 2% CHX showed antimicrobial effects against all tested microorganisms but zones of inhibition were smaller. The best results in root canal walls cleaning were obtained in the group where the irrigant was 15% EDTA (score 2.33. In 5.25% NaOCl, 2.5% NaOCl and 2% CHX groups, there was more smear layer (score 4 and 5. Conclusion. 2% chlorhexidine digluconate showed strong antimicrobial effect on the tested microorganisms, but was not effective in cleaning root canal walls.

  3. Antimicrobial Activity of Glass lonomer Cement Incorporated with Chlorhexidine-Loaded Zeolite Nanoparticles.

    Science.gov (United States)

    Kim, Hyun-Jin; Son, Jun Sik; Kim, Kyo-Han; Kwon, Tae-Yub

    2016-02-01

    A functional dental restorative system with antimicrobial properties was developed using zeolite (ZE) nanoparticles (NPs) as a drug delivery carrier. ZE NPs loaded with chlorhexidine (CHX) were prepared using the ionic immobilization method. The resulting CHX-loaded ZE NPs were then incorporated into commercial dental glass ionomer cement (GIC). The average size of the CHX-loaded ZE NPs was about 100 to 200 nm, and the NPs were dispersed homogeneously in the GIC. The in vitro release profile of encapsulated GIC containing CHX showed an early release burst of approximately 30% of the total CHX by day 7, whereas GIC containing CHX-loaded ZE NPs showed a sustained release of CHX without the early release burst in a 4-week immersion study. The agar diffusion test results showed that the GIC incorporated with CHX-loaded ZE NPs showed a larger growth inhibition zone of Streptococcus mutans than GIC alone, indicating that this innovative delivery platform potently imparted antimicrobial activity to the GIC. Moreover, these findings suggest that a range of antimicrobial drugs that inhibit the growth of oral bacteria can be incorporated efficiently into dental GIC using CHX-loaded ZE NPs.

  4. Evaluation of antimicrobial efficacy of sodium hypochlorite, propolis, octenidine dihydrochloride and chlorhexidine on microorganisms

    Directory of Open Access Journals (Sweden)

    Demet Altunbaş

    2011-09-01

    Full Text Available

    ABSTRACT

    Objectives: The aim of this present study was to evaluate the antimicrobial effect of  2.5% sodium hypochlorite (NaOCl, 12.5% propolis, 25% propolis, octenidine dihydrochloride (OCT and 2% chlorhexidine (CHX on microorganisms with different structural characteristics.

    Materials and Methods: S. aureus, E. faecalis, E. coli and C. albicans were included in the study. Pre-sterilized paper discs (6 mm in diameter were soaked with the test solutions and placed on the plates, following Muller-Hinton agar plates were inoculated with the microbial suspensions. Then zones of inhibition were recorded and the results were analysed statistically. 2.5% NaOCl, 2% CHX and OCT produced inhibitory zones against all microorganisms tested. Statistical analysis was carried out with analyses of variance (ANOVA. Differences were identified by post-hoc Bonferroni test. The level of significance was set at p=0.05.

    Results: NaCl was ineffective against all microorganisms; however, 2.5% NaOCl, 2% CHX and OCT produced inhibitory zones against all microorganisms tested. 2.5% NaOCl and 2% CHX showed significantly larger average zones of inhibition compared to the other experimental irrigants (p<0.05. While 12.5% propolis extract produced only slight inhibition on S. aureus, 25% propolis extract was effective on S. aureus, E. faecalis and C. albicans.

    Conclusions: The present study showed that 2.5% NaOCl and 2% chlorhexidine had superior antimicrobial effects than other irrigants used.

    Key words: Chlorhexidine, microorganisms, sodium hypochlorite, octenidine dihydrochloride, propolis.

     

  5. Antibacterial and residual antimicrobial activities against Enterococcus faecalis biofilm: A comparison between EDTA, chlorhexidine, cetrimide, MTAD and QMix

    OpenAIRE

    Zhang, Rui; Chen, Min; Lu, Yan; Guo, Xiangjun; Qiao, Feng; Wu, Ligeng

    2015-01-01

    We compared the antibacterial and residual antimicrobial activities of five root canal irrigants (17% EDTA,2% chlorhexidine,0.2% cetrimide, MTAD, and QMix) in a model of Enterococcus faecalis biofilm formation. Sixty dentin blocks with 3-week E. faecalis biofilm were divided into six equal groups and flushed with irrigant for 2 min or left untreated. A blank control group was also established. Antibacterial activities of the irrigants were evaluated by counting colony forming units. To test r...

  6. Agents containing chlorhexidine in dentistry

    OpenAIRE

    Lebedeva S.N.; Zemlyanichenko М.К.

    2011-01-01

    Aclinical definition of the efficacy of chlorhexidine-containing means for reducing the risk of dental caries and gingivitis with plastic caps. Chlorhexidine is an effective antimicrobial agent for the formation of individual programs for the prevention of dental caries

  7. Broad spectrum antibiotic compounds and use thereof

    Energy Technology Data Exchange (ETDEWEB)

    Koglin, Alexander; Strieker, Matthias

    2016-07-05

    The discovery of a non-ribosomal peptide synthetase (NRPS) gene cluster in the genome of Clostridium thermocellum that produces a secondary metabolite that is assembled outside of the host membrane is described. Also described is the identification of homologous NRPS gene clusters from several additional microorganisms. The secondary metabolites produced by the NRPS gene clusters exhibit broad spectrum antibiotic activity. Thus, antibiotic compounds produced by the NRPS gene clusters, and analogs thereof, their use for inhibiting bacterial growth, and methods of making the antibiotic compounds are described.

  8. Antimicrobial activity of calcium hydroxide and chlorhexidine on intratubular Candida albicans

    OpenAIRE

    Jacques Rezende Delgado, Ronan; Helena Gasparoto, Thaís; Renata Sipert, Carla; Ramos Pinheiro, Claudia; Gomes de Moraes, Ivaldo; Brandão Garcia, Roberto; Antônio Hungaro Duarte, Marco; Monteiro Bramante, Clóvis; Aparecido Torres, Sérgio; Pompermaier Garlet, Gustavo; Paula Campanelli, Ana; Bernardineli, Norberti

    2013-01-01

    This study investigated the efficacy of calcium hydroxide and chlorhexidine gel for the elimination of intratubular Candida albicans (C. albicans). Human single-rooted teeth contaminated with C. albicans were treated with calcium hydroxide, 2% chlorhexidine gel, calcium hydroxide plus 2% chlorhexidine gel, or saline (0.9% sodium chloride) as a positive control. The samples obtained at depths of 0–100 and 100–200 µm from the root canal system were analyzed for C. albicans load by counting the ...

  9. Comparison of antimicrobial efficacy of chlorhexidine and combination mouth rinse in reducing the Mutans streptococcus count in plaque

    Directory of Open Access Journals (Sweden)

    Laxmi S Lakade

    2014-01-01

    Full Text Available Background: The removal of plaque is utmost important to control dental caries. But in children, factors like lack of dexterity, individual motivation and monitoring limit the effectiveness of tooth brushing. This necessitates the use of chemotherapeutic agents for control of plaque. Aims: To compare the antimicrobial efficacy of 0.2% chlorhexidine mouth rinse and mouth rinse containing 0.03% triclosan, 0.05% sodium fluoride, and 5% xylitol in reducing the Mutans streptococcus count in plaque. Materials and Methods: Thirty healthy children aged 8-10 years with dmft (decay component of three or four were selected. They were divided randomly into two groups: The control or chlorhexidine group and the study group or combination mouth rinse. Both the groups practiced rinsing with respective mouth wash for 1 min for 15 d twice a day. The plaque samples were collected and after incubation Mutans streptococcus count was estimated on the strips from the Dentocult SM kit and evaluated using manufacture′s chart. Statistical Analysis Used: Wilcoxon matched pairs signed ranks test and Mann-Whitney U test were used to analyze the findings. Results: Statistically significant reduction in the Mutans streptococci count in the plaque was seen in the control and study group from baseline level. But when both the groups were compared, the antimicrobial effect of chlorhexidine was more.

  10. Novel water-based antiseptic lotion demonstrates rapid, broad-spectrum kill compared with alcohol antiseptic.

    Science.gov (United States)

    Czerwinski, Steven E; Cozean, Jesse; Cozean, Colette

    2014-01-01

    A novel alcohol-based antiseptic and a novel water-based antiseptic lotion, both with a synergistic combination of antimicrobial ingredients containing 0.2% benzethonium chloride, were evaluated using the standard time-kill method against 25 FDA-specified challenge microorganisms. The purpose of the testing was to determine whether a non-alcohol product could have equivalent rapid and broad-spectrum kill to a traditional alcohol sanitizer. Both the alcohol- and water-based products showed rapid and broad-spectrum antimicrobial activity. The average 15-s kill was 99.999% of the challenge organism for the alcohol-based antiseptic and 99.971% for the water-based antiseptic. The alcohol-based product demonstrated 100% of peak efficacy (60s) within the first 15s, whereas the water-based product showed 99.97%. The novel alcohol-based antiseptic reduced concentrations of 100% of organisms by 99.999%, whereas the water-based antiseptic lotion showed the same reduction for 96% of organisms. A novel water-based antiseptic product demonstrated equivalent rapid, broad-spectrum antimicrobial activity to an alcohol-based sanitizer and provided additional benefits of reduced irritation, persistent effect, and greater efficacy against common viruses. The combination of rapid, broad-spectrum immediate kill and persistent efficacy against pathogens may have significant clinical benefit in limiting the spread of disease.

  11. Broad spectrum anthelmintic potential of Cassia plants

    Institute of Scientific and Technical Information of China (English)

    Suman Kundu; Saptarshi Roy; Larisha Mawkhleing Lyndem

    2014-01-01

    Objective: To study the in vitro anthelmintic efficacy of Cassia alata (C. alata), Cassia(C. angustifolia) and Cassia occidentalis (C. occidentalis). angustifolia Methods: Crude ethanol extract from leaves of the three plants were prepared in rotary evaporator and different concentrations (10, 20 and 40 mg/mL) of leaf extracts were used for treatment on different representatives of helminthes (Heterakis gallinarum, Raillietina tetragona and Catatropis sp.) from domestic fowl (Gallus gallus domesticus). Loss of motility and death were monitored frequently.Results: C. alata showed early paralysis in all worms treated followed by C. angustifolia. C. occidentalis in combination with C. alata together caused early paralysis in all treated worms than the combination of C. alata with C. angustfolia. While Heterakis gallinarum in control survived for (81.33±2.07) h, treated worms lost their motility at (5.71±0.10) h, (6.60±0.86) h and (13.95±0.43) h with C. angustifolia, C. alata and C. occidentalis respectively at a concentration of 40 mg/mL which showed better efficacy than albendazole. Catatropis sp. survival period was (26.49±1.38) h in control, but with plant treatment, it lost its motility in just (0.57±0.08) h, (1.00±0.12) h and (1.47±0.40) h at 40 mg/mL concentration of C. alata, C. angustifolia and C. occidentalis respectively.Raillietina tetragona on the other hand became paralysed at (1.68±0.27) h, (2.95±0.29) h and (4.13±0.31) h with above concentrations treated with three plants respectively, however in control it survived up to (81.93±4.71) h.Conclusions:This present study indicated broad spectrum vermifugal activity of all plants tested.

  12. Antibiofilm Peptides: Potential as Broad-Spectrum Agents.

    Science.gov (United States)

    Pletzer, Daniel; Hancock, Robert E W

    2016-10-01

    The treatment of bacterial diseases is facing twin threats, with increasing bacterial antibiotic resistance and relatively few novel compounds or strategies under development or entering the clinic. Bacteria frequently grow on surfaces as biofilm communities encased in a polymeric matrix. The biofilm mode of growth is associated with 65 to 80% of all clinical infections. It causes broad adaptive changes; biofilm bacteria are especially (10- to 1,000-fold) resistant to conventional antibiotics and to date no antimicrobials have been developed specifically to treat biofilms. Small synthetic peptides with broad-spectrum antibiofilm activity represent a novel approach to treat biofilm-related infections. Recent developments have provided evidence that these peptides can inhibit even developed biofilms, kill multiple bacterial species in biofilms (including the ESKAPE [Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species] pathogens), show strong synergy with several antibiotics, and act by targeting a universal stress response in bacteria. Thus, these peptides represent a promising alternative treatment to conventional antibiotics and work effectively in animal models of biofilm-associated infections. PMID:27068589

  13. Antibacterial and residual antimicrobial activities against Enterococcus faecalis biofilm: A comparison between EDTA, chlorhexidine, cetrimide, MTAD and QMix

    Science.gov (United States)

    Zhang, Rui; Chen, Min; Lu, Yan; Guo, Xiangjun; Qiao, Feng; Wu, Ligeng

    2015-08-01

    We compared the antibacterial and residual antimicrobial activities of five root canal irrigants (17% EDTA,2% chlorhexidine,0.2% cetrimide, MTAD, and QMix) in a model of Enterococcus faecalis biofilm formation. Sixty dentin blocks with 3-week E. faecalis biofilm were divided into six equal groups and flushed with irrigant for 2 min or left untreated. A blank control group was also established. Antibacterial activities of the irrigants were evaluated by counting colony forming units. To test residual antimicrobial activities, 280 dentin blocks were divided into seven equal groups and flushed with irrigant for 2 min or left untreated and then incubated with E. faecalis suspension for 48 h, or used as a blank. No bacteria were observed in the blank control group. The number of viable E. faecalis was significantly fewer in the irrigant-treated groups compared with the untreated control (P < 0.05). Among the five irrigants, QMix had the strongest antibacterial activity. Residual antimicrobial activities of CHX were significantly higher at 12 h, 24 h and 36 h compared to untreated control (P < 0.05). All five root canal irrigants were effective to some extent against E. faecalis, but QMix and CHX had the strongest, and CHX the longest (up to 36 h), antimicrobial activity.

  14. Broad-spectrum antimicrobial activity of human intestinal defensin 5.

    OpenAIRE

    Porter, E M; van Dam, E; Valore, E V; Ganz, T

    1997-01-01

    Defensins are antibiotic peptides expressed in human and animal myeloid and epithelial cells. Due to the limited availability of natural peptides, the properties of human epithelial defensins have not been studied. We assayed the microbicidal activity of recombinant human intestinal defensin 5 (rHD-5) in the presence of salt (O to 150 mM NaCl) with varied pH (pH 5.5 to pH 8.5) and trypsin (25 and 250 microg/ml). rHD-5 exhibits microbicidal activity against Listeria monocytogenes, Escherichia ...

  15. Resistance of nanobacteria isolated from urinary and kidney stones to broad-spectrum antibiotics.

    Directory of Open Access Journals (Sweden)

    Hadi Sardarabadi

    2014-08-01

    Full Text Available Nanoscopic life forms called Nanobacteria or calcifying nanoparticles (CNP are unconventional agents. These novel organisms are very small (0.1 to 0.5 microns and possess unusual properties such as high resistance to heat and routine antimicrobial agents. Nanobacteria are 100 times smaller than bacteria and protected by a shell of apatite, so they could be as candidate for emerging and progress of in vivo pathological calcification. In this study, the inhibitory effect of broad-spectrum antibiotics on growth of these new forms of life has been investigated.Powdered urinary and kidney stones were demineralized with HCl and neutralized with appropriate buffers and became filtered. Finally suspension was incubated in DMEM medium with Fetal Bovine Serum (FBS and broad-spectrum antibiotics (100U/ml for penicillin and 100μg/ml for streptomycin for 60 days.In the presence of broad-spectrum antibiotics, Scanning Electron Micrographs (SEM showed a spherical shape of these nanobacteria. Also, Energy Dispersive X-ray spectroscopy (EDS showed a pick for calcium and phosphor. Transmission Electron Microscopy (TEM results illustrated cover around the nanobacteria.The growth of calcifying nanoparticles after adding the broad-spectrum antibiotics may be due to their apatite hard shells supporting them against penetration of the antibiotics.

  16. In vitro antimicrobial activity of a commercial ear antiseptic containing chlorhexidine and Tris-EDTA.

    Science.gov (United States)

    Guardabassi, Luca; Ghibaudo, Giovanni; Damborg, Peter

    2010-06-01

    Minimum bactericidal concentrations (MBCs) of a commercial ear antiseptic containing chlorhexidine 0.15% and Tris-EDTA (Otodine) were determined by broth microdilution for 150 isolates representing the most common pathogens associated with canine otitis. The microorganisms were classified into three groups according to their levels of susceptibility. The most susceptible group included Staphylococcus pseudintermedius, Malassezia pachydermatis, Streptococcus canis and Corynebacterium auriscanis, which were generally killed by 1 : 64 dilution of the antiseptic product (MBC = 23/0.8 microg/mL of chlorhexidine/Tris-EDTA). The most resistant organism was Proteus mirabilis, which survived up to 1 : 8 dilution of the product (MBC = 375/12 microg/mL). Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus displayed intermediate MBCs ranging between 188/6 and 47/1.5 microg/mL. Interestingly, S. pseudintermedius was more susceptible than S. aureus, and no significant difference was observed between meticillin-resistant and meticillin-susceptible isolates within each species, indicating that antiseptic use is unlikely to co-select for meticillin resistance. Although the concentrations required for killing (MBCs) varied considerably with microorganism type, the combination of chlorhexidine 0.15% and Tris-EDTA was active against all the pathogens most commonly involved in canine otitis. PMID:20030799

  17. In vitro antimicrobial activity of a commercial ear antiseptic containing chlorhexidine and Tris-EDTA.

    Science.gov (United States)

    Guardabassi, Luca; Ghibaudo, Giovanni; Damborg, Peter

    2010-06-01

    Minimum bactericidal concentrations (MBCs) of a commercial ear antiseptic containing chlorhexidine 0.15% and Tris-EDTA (Otodine) were determined by broth microdilution for 150 isolates representing the most common pathogens associated with canine otitis. The microorganisms were classified into three groups according to their levels of susceptibility. The most susceptible group included Staphylococcus pseudintermedius, Malassezia pachydermatis, Streptococcus canis and Corynebacterium auriscanis, which were generally killed by 1 : 64 dilution of the antiseptic product (MBC = 23/0.8 microg/mL of chlorhexidine/Tris-EDTA). The most resistant organism was Proteus mirabilis, which survived up to 1 : 8 dilution of the product (MBC = 375/12 microg/mL). Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus displayed intermediate MBCs ranging between 188/6 and 47/1.5 microg/mL. Interestingly, S. pseudintermedius was more susceptible than S. aureus, and no significant difference was observed between meticillin-resistant and meticillin-susceptible isolates within each species, indicating that antiseptic use is unlikely to co-select for meticillin resistance. Although the concentrations required for killing (MBCs) varied considerably with microorganism type, the combination of chlorhexidine 0.15% and Tris-EDTA was active against all the pathogens most commonly involved in canine otitis.

  18. Broad Spectrum Sanitizing Wipes with Food Additives Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Microcide proposes to develop novel multipurpose non-toxic sanitizing wipes that are aqueous based, have shelf life of 3-5 years, have broad spectrum microbicidal...

  19. Characteristics of doripenem: a new broad-spectrum antibiotic

    Directory of Open Access Journals (Sweden)

    Francisco Alvarez-Lerma

    2009-05-01

    Full Text Available Francisco Alvarez-Lerma1, Santiago Grau2, Olivia Ferrández21Intensive Care Unit, 2Pharmacy Department, Hospital Del Mar, Barcelona, SpainAbstract: Doripenem (S-4661 is a new parenteral antibiotic from the carbapenem class; similarly to imipenem and meropenem, it has a broad-spectrum activity against Gram-positive, Gram-negative, and anaerobic bacteria. It is active against multiresistant Gram-negative bacilli such as extended-spectrum beta-lactamase-producing (ESBL Gram-negative Enterobacteriaceae and nonfermentative Gram-negative bacilli including some strains of Pseudomonas aeruginosa that are resistant to other carbapenems. Doripenem’s chemical structure is similar to that of meropenem (substitution of one sulfamoxil-aminomethyl chain for the dimethyl-carboxyl chain, and has one 1-beta-methyl chain which provides resistance to dehydropeptidase-I enzyme. The clinical trials conducted so far have focused on the treatment of severe infections such as complicated intra-abdominal infections, complicated urinary tract infections and pyelonephritis, nosocomial pneumonia, and ventilator-associated pneumonia. Given its activity profile and the results from the clinical trials, this antibiotic may be used for empirical treatment of multibacterial infections produced by potentially multiresistant Gram-negative bacilli. In 2007, the US Food and Drug Administration approved the use of doripenem for the treatment of complicated intra-abdominal infections and complicated urinary tract infections. The European Medicines Agency has approved the use of doripenem for the same indications in addition to nosocomial pneumonia regardless of whether it is ventilator-associated or not.Keywords: doripenem, antimicrobial activity, clinical efficacy, pharmacokinetics, tolerability

  20. Antimicrobial activity of Calendula officinalis, Camellia sinensis and chlorhexidine against the adherence of microorganisms to sutures after extraction of unerupted third molars

    OpenAIRE

    FARIA, Raquel Lourdes; CARDOSO, Lincoln Marcelo Lourenço; Akisue, Gokithi; PEREIRA, Cristiane Aparecida; Junqueira, Juliana Campos; Jorge, Antonio Olavo Cardoso; SANTOS JÚNIOR, Paulo Villela

    2011-01-01

    Objective The objective of this study was to compare the antimicrobial effect of mouthwashes containing Calendula officinalis L., Camellia sinensis (L.) Kuntze and 0.12% chlorhexidine digluconate on the adherence of microorganisms to suture materials after extraction of unerupted third molars. Material and Methods Eighteen patients with unerupted maxillary third molars indicated for extraction were selected (n=6 per mouthwash). First, the patients were subjected to extraction of the left toot...

  1. Perioperative chlorhexidine allergy: Is it serious?

    OpenAIRE

    Abdallah, Claude

    2015-01-01

    Chlorhexidine is an antiseptic agent, commonly used, in many different preparations, and for multiple purposes. Despite its superior antimicrobial properties, chlorhexidine is a potentially allergenic substance. The following is a review of the current evidence-based knowledge of allergic reactions to chlorhexidine associated with surgical and interventional procedures.

  2. Targeting an Essential GTPase Obg for the Development of Broad-Spectrum Antibiotics.

    Science.gov (United States)

    Bonventre, Josephine A; Zielke, Ryszard A; Korotkov, Konstantin V; Sikora, Aleksandra E

    2016-01-01

    A promising new drug target for the development of novel broad-spectrum antibiotics is the highly conserved small GTPase Obg (YhbZ, CgtA), a protein essential for the survival of all bacteria including Neisseria gonorrhoeae (GC). GC is the agent of gonorrhea, a prevalent sexually transmitted disease resulting in serious consequences on reproductive and neonatal health. A preventive anti-gonorrhea vaccine does not exist, and options for effective antibiotic treatments are increasingly limited. To address the dire need for alternative antimicrobial strategies, we have designed and optimized a 384-well GTPase assay to identify inhibitors of Obg using as a model Obg protein from GC, ObgGC. The assay was validated with a pilot screen of 40,000 compounds and achieved an average Z' value of 0.58 ± 0.02, which suggests a robust assay amenable to high-throughput screening. We developed secondary assessments for identified lead compounds that utilize the interaction between ObgGC and fluorescent guanine nucleotide analogs, mant-GTP and mant-GDP, and an ObgGC variant with multiple alterations in the G-domains that prevent nucleotide binding. To evaluate the broad-spectrum potential of ObgGC inhibitors, Obg proteins of Klebsiella pneumoniae and methicillin-resistant Staphylococcus aureus were assessed using the colorimetric and fluorescence-based activity assays. These approaches can be useful in identifying broad-spectrum Obg inhibitors and advancing the therapeutic battle against multidrug resistant bacteria. PMID:26848972

  3. Antimicrobial activity of Calendula officinalis, Camellia sinensis and chlorhexidine against the adherence of microorganisms to sutures after extraction of unerupted third molars

    Directory of Open Access Journals (Sweden)

    Raquel Lourdes Faria

    2011-10-01

    Full Text Available OBJECTIVE: The objective of this study was to compare the antimicrobial effect of mouthwashes containing Calendula officinalis L., Camellia sinensis (L. Kuntze and 0.12% chlorhexidine digluconate on the adherence of microorganisms to suture materials after extraction of unerupted third molars. MATERIAL AND METHODS: Eighteen patients with unerupted maxillary third molars indicated for extraction were selected (n=6 per mouthwash. First, the patients were subjected to extraction of the left tooth and instructed not to use any type of antiseptic solution at the site of surgery (control group. After 15 days, the right tooth was extracted and the patients were instructed to use the Calendula officinalis, Camellia sinensis or chlorhexidine mouthwash during 1 week (experimental group. For each surgery, the sutures were removed on postoperative day 7 and placed in sterile phosphate-buffered saline. Next, serial dilutions were prepared and seeded onto different culture media for the growth of the following microorganisms: blood agar for total microorganism growth; Mitis Salivarius bacitracin sucrose agar for mutans group streptococci; mannitol agar for Staphylococcus spp.; MacConkey agar for enterobacteria and Pseudomonas spp., and Sabouraud dextrose agar containing chloramphenicol for Candida spp. The plates were incubated during 24-48 h at 37ºC for microorganism count (CFU/mL. RESULTS: The three mouthwashes tested reduced the number of microorganisms adhered to the sutures compared to the control group. However, significant differences between the control and experimental groups were only observed for the mouthwash containing 0.12% chlorhexidine digluconate. CONCLUSIONS: Calendula officinalis L. and Camellia sinensis (L. Kuntze presented antimicrobial activity against the adherence of microorganisms to sutures but were not as efficient as chlorhexidine digluconate.

  4. Broad spectrum antiangiogenic treatment for ocular neovascular diseases.

    Directory of Open Access Journals (Sweden)

    Ofra Benny

    Full Text Available UNLABELLED: Pathological neovascularization is a hallmark of late stage neovascular (wet age-related macular degeneration (AMD and the leading cause of blindness in people over the age of 50 in the western world. The treatments focus on suppression of choroidal neovascularization (CNV, while current approved therapies are limited to inhibiting vascular endothelial growth factor (VEGF exclusively. However, this treatment does not address the underlying cause of AMD, and the loss of VEGF's neuroprotective can be a potential side effect. Therapy which targets the key processes in AMD, the pathological neovascularization, vessel leakage and inflammation could bring a major shift in the approach to disease treatment and prevention. In this study we have demonstrated the efficacy of such broad spectrum antiangiogenic therapy on mouse model of AMD. METHODS AND FINDINGS: Lodamin, a polymeric formulation of TNP-470, is a potent broad-spectrum antiangiogenic drug. Lodamin significantly reduced key processes involved in AMD progression as demonstrated in mice and rats. Its suppressive effects on angiogenesis, vascular leakage and inflammation were studied in a wide array of assays including; a Matrigel, delayed-type hypersensitivity (DTH, Miles assay, laser-induced CNV and corneal micropocket assay. Lodamin significantly suppressed the secretion of various pro-inflammatory cytokines in the CNV lesion including monocyte chemotactic protein-1 (MCP-1/Ccl2. Importantly, Lodamin was found to regress established CNV lesions, unlike soluble fms-like tyrosine kinase-1 (sFlk-1. The drug was found to be safe in mice and have little toxicity as demonstrated by electroretinography (ERG assessing retinal and by histology. CONCLUSIONS: Lodamin, a polymer formulation of TNP-470, was identified as a first in its class, broad-spectrum antiangiogenic drug that can be administered orally or locally to treat corneal and retinal neovascularization. Several unique properties

  5. The broad spectrum revisited: Evidence from plant remains

    OpenAIRE

    Weiss, Ehud; Wetterstrom, Wilma; Nadel, Dani; Bar-Yosef, Ofer

    2004-01-01

    The beginning of agriculture is one of the most important developments in human history, with enormous consequences that paved the way for settled life and complex society. Much of the research on the origins of agriculture over the last 40 years has been guided by Flannery's [Flannery, K. V. (1969) in The Domestication and Exploitation of Plants and Animals, eds. Ucko, P. J. & Dimbleby, G. W. (Duckworth, London), pp. 73–100] “broad spectrum revolution” (BSR) hypothesis, which posits that the...

  6. Effect of Different Obturation Materials on Residual Antimicrobial Activity of 2% Chlorhexidine in Dentin at Different Time Intervals: An Ex Vivo Study

    Directory of Open Access Journals (Sweden)

    Behnam Bolhari

    2016-03-01

    Full Text Available Objectives: The aim of this study was to evaluate the effect of gutta percha/AH26 and Resilon/RealSeal SE on residual antimicrobial activity of chlorhexidine (CHX in human root dentin and suggest the best filling material when CHX is used as final irrigant.Materials and Methods: One-hundred and forty-four single-rooted human teeth were selected for this study. Canals were instrumented to the apical size #35. Smear layer was removed using 5.25% NaOCl and 17% EDTA and then 108 teeth were irrigated with 2% CHX and randomly divided into three groups of gutta percha/AH26, Resilon/RealSeal SE and positive controls. Each group was divided into three subgroups for different time intervals (one, three and six weeks. Thirty-six teeth, as negative controls, were irrigated with saline and obturated with gutta percha/AH26 and Resilon/RealSeal SE. Dentin powder was prepared at the afore-mentioned intervals. After exposure to Enterococcus faecalis for 24 hours, colony forming units (CFUs were counted and residual antimicrobial activity was calculated. The data were analyzed using the Kruskal Wallis test and one-way ANOVA. The significance level was set at P<0.05.Results: The antimicrobial activity of CHX gradually decreased in a time-dependent manner but it maintained over 95% of its antimicrobial activity after six weeks. Moreover, Resilon/RealSeal SE significantly decreased the antimicrobial activity of CHX in comparison with gutta-percha/AH26 (P<0.05.Conclusion: After a final irrigation with CHX, gutta-percha/AH26 is a better choice for root canal obturation.Key words: Chlorhexidine; Gutta-Percha; Epoxy resin AH-26; Resilon sealer. 

  7. Chlorhexidine--pharmacology and clinical applications.

    Science.gov (United States)

    Lim, K-S; Kam, P C A

    2008-07-01

    Chlorhexidine is a widely used skin antisepsis preparation and is an ingredient in toothpaste and mouthwash. It is an especially effective antiseptic when combined with alcohol. Its antimicrobial effects persist because it is binds strongly to proteins in the skin and mucosa, making it an effective antiseptic ingredient for handwashing, skin preparation for surgery and the placement of intravascular access. Catheters impregnated with chlorhexidine and antimicrobial agents can reduce the incidence of catheter-related bloodstream infections. Contact dermatitis related to chlorhexidine is not common in health care workers. The incidence of contact dermatitis to chlorhexidine in atopic patients is approximately 2.5 to 5.4%. Acute hypersensitivity reactions to chlorhexidine are often not recognised and therefore may be underreported. This review discusses the pharmacology, microbiology, clinical applications and adverse effects of chlorhexidine.

  8. Comparative evaluation of the antimicrobial activity of natural extracts of Morinda citrifolia, papain and aloe vera (all in gel formulation), 2% chlorhexidine gel and calcium hydroxide, against Enterococcus faecalis: An in vitro study

    OpenAIRE

    Anuj Bhardwaj; Suma Ballal; Natanasabapathy Velmurugan

    2012-01-01

    Aim: A comparative evaluation of the antimicrobial activity of natural extracts of Morinda citrifolia, papain, and aloe vera (all in gel formulations), 2% chlorhexidine gel and calcium hydroxide, against Enterococcus faecalis-an in vitro study. Materials and Methods: The antimicrobial efficacy was assessed in vitro using dentin shavings collected at 2 depths of 200 and 400 μm. The total colony forming units at the end of 1, 3, and 5 days were assessed. Results: The overall percentage ...

  9. Broad spectrum moderators and advanced reflector filters using 208Pb

    DEFF Research Database (Denmark)

    Schönfeldt, Troels; Batkov, K.; Klinkby, Esben Bryndt;

    2015-01-01

    thermalizing property of 208Pb to design a broad spectrum moderator, i.e. a moderator which emits thermal and cold neutrons from the same position. Using 208Pb as a reflector filter material is shown to be slightly less efficient than a conventional beryllium reflector filter. However, when surrounding......Cold and thermal neutrons used in neutrons scattering experiments are produced in nuclear reactors and spallation sources. The neutrons are cooled to thermal or cold temperatures in thermal and cold moderators, respectively. The present study shows that it is possible to exploit the poor...... the reflector filter by a cold moderator it is possible to regain the neutrons with wavelengths below the Bragg edge, which are suppressed in the beryllium reflector filter. In both the beryllium and lead case surrounding the reflector filter with a cold moderator increases the cold brightness significantly...

  10. Genetically Engineered Broad-Spectrum Disease Resistance in Tomato

    Science.gov (United States)

    Oldroyd, Giles E. D.; Staskawicz, Brian J.

    1998-08-01

    Resistance in tomato to the bacterial pathogen Pseudomonas syringae pathovar tomato requires Pto and Prf. Mutations that eliminate Prf show a loss of both Pto resistance and sensitivity to the organophosphate insecticide fenthion, suggesting that Prf controls both phenotypes. Herein, we report that the overexpression of Prf leads to enhanced resistance to a number of normally virulent bacterial and viral pathogens and leads to increased sensitivity to fenthion. These plants express levels of salicylic acid comparable to plants induced for systemic acquired resistance (SAR) and constitutively express pathogenesis related genes. These results suggest that the overexpression of Prf activates the Pto and Fen pathways in a pathogen-independent manner and leads to the activation of SAR. Transgene-induced SAR has implications for the generation of broad spectrum disease resistance in agricultural crop plants.

  11. Antibiotic combination therapy can select for broad-spectrum multidrug resistance in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Vestergaard, Martin; Paulander, Wilhelm; Marvig, Rasmus L.;

    2016-01-01

    Combination therapy with several antibiotics is one strategy that has been applied in order to limit the spread of antimicrobial resistance. We compared the de novo evolution of resistance during combination therapy with the β-lactam ceftazidime and the fluoroquinolone ciprofloxacin...... to a broad-spectrum resistance phenotype that decreased susceptibility to the combination of drugs applied during selection as well as to unrelated antibiotic classes. Mutants isolated after single-drug exposure displayed narrow-spectrum resistance and carried mutations in the MexCD–OprJ efflux pump...... regulator gene nfxB conferring ciprofloxacin resistance, or in the gene encoding the non-essential penicillin-binding protein DacB conferring ceftazidime resistance. Reconstruction of resistance mutations by allelic replacement and in vitro fitness assays revealed that in contrast to single antibiotic use...

  12. Surveillance of broad-spectrum antibiotic prescription in Singaporean hospitals: a 5-year longitudinal study.

    Directory of Open Access Journals (Sweden)

    Yi-Xin Liew

    Full Text Available BACKGROUND: Inappropriate prescription of antibiotics may contribute towards higher levels antimicrobial resistance. A key intervention for improving appropriate antibiotic prescription is surveillance of prescription. This paper presents the results of a longitudinal surveillance of broad-spectrum antibiotic prescription in 5 public-sector hospitals in Singapore from 2006 to 2010. METHODOLOGY/PRINCIPAL FINDINGS: Quarterly antibiotic prescription data were obtained and converted to defined daily doses (DDDs per 1,000 inpatient-days. The presence of significant trends in antibiotic prescription over time for both individual and combined hospitals was tested by regression analysis and corrected for autocorrelation between time-points. Excluding fluoroquinolones, there was a significant increase in prescription of all monitored antibiotics from an average of 233.12 defined daily doses (DDD/1,000 inpatient-days in 2006 to 254.38 DDD/1,000 inpatient-days in 2010 (Coefficient = 1.13, 95%CI: 0.16-2.09, p = 0.025. Increasing utilization of carbapenems, piperacillin/tazobactam, and Gram-positive agents were seen in the majority of the hospitals, while cephalosporins were less prescribed over time. The combined expenditure for 5 hospitals increased from USD9.9 million in 2006 to USD16.7 million in 2010. CONCLUSIONS/SIGNIFICANCE: The rate of prescription of broad-spectrum antibiotics in Singaporean hospitals is much higher compared to those of European hospitals. This may be due to high rates of antimicrobial resistance. The increase in expenditure on monitored antibiotics over the past 5 years outstripped the actual increase in DDD/1,000 inpatient-days of antibiotics prescribed. Longitudinal surveillance of antibiotic prescription on a hospital and countrywide level is important for detecting trends for formulating interventions or policies. Further research is needed to understand the causes for the various prescription trends and to act on these where

  13. Comparative evaluation of antimicrobial efficacy of QMix TM 2 in 1, sodium hypochlorite, and chlorhexidine against Enterococcus faecalis and Candida albicans

    Directory of Open Access Journals (Sweden)

    Soujanya Elakanti

    2015-01-01

    Full Text Available Aim/Objective: The aim of this study is to compare the antimicrobial efficacy of QMix TM 2 in 1, sodium hypochlorite (NaOCl, and chlorhexidine (CHX against Enterococcus faecalis and Candida albicans. Materials and Methods: Eighty freshly extracted, single-rooted human mandibular premolar teeth were instrumented and autoclaved. Samples were divided into two groups of 40 teeth each based on the type of microorganism used. Group I was inoculated with E. faecalis and Group II with C. albicans and incubated for 3 days. Each group was subdivided into four subgroups based on the type of irrigant used. Group IA, IIA, 5.25% NaOCl; Group IB, IIB, 2% CHX; Group IC, IIC, QMix TM 2 in 1; and Group ID, IID, 0.9% saline (the control group. Ten microliters of the sample from each canal was taken and was placed on Brain Heart Infusion agar and Sabouraud dextrose agar. The plates were incubated at 37°C for 24 h and colony forming units (CFUs that were grown were counted. Data was analyzed with analysis of variance (ANOVA followed by post-hoc Games-Howell test. Results: The greatest antimicrobial effects were observed in samples treated with QMix TM 2 in 1 (P 0.001 against E. faecalis and C. albicans. Conclusion: QMix TM 2 in 1 demonstrated significant antimicrobial efficacy against E. faecalis and C. albicans.

  14. Broad spectrum microarray for fingerprint-based bacterial species identification

    Directory of Open Access Journals (Sweden)

    Frey Jürg E

    2010-02-01

    Full Text Available Abstract Background Microarrays are powerful tools for DNA-based molecular diagnostics and identification of pathogens. Most target a limited range of organisms and are based on only one or a very few genes for specific identification. Such microarrays are limited to organisms for which specific probes are available, and often have difficulty discriminating closely related taxa. We have developed an alternative broad-spectrum microarray that employs hybridisation fingerprints generated by high-density anonymous markers distributed over the entire genome for identification based on comparison to a reference database. Results A high-density microarray carrying 95,000 unique 13-mer probes was designed. Optimized methods were developed to deliver reproducible hybridisation patterns that enabled confident discrimination of bacteria at the species, subspecies, and strain levels. High correlation coefficients were achieved between replicates. A sub-selection of 12,071 probes, determined by ANOVA and class prediction analysis, enabled the discrimination of all samples in our panel. Mismatch probe hybridisation was observed but was found to have no effect on the discriminatory capacity of our system. Conclusions These results indicate the potential of our genome chip for reliable identification of a wide range of bacterial taxa at the subspecies level without laborious prior sequencing and probe design. With its high resolution capacity, our proof-of-principle chip demonstrates great potential as a tool for molecular diagnostics of broad taxonomic groups.

  15. Steps toward broad-spectrum therapeutics: discovering virulence-associated genes present in diverse human pathogens

    Directory of Open Access Journals (Sweden)

    de Rochefort Anna

    2009-10-01

    Full Text Available Abstract Background New and improved antimicrobial countermeasures are urgently needed to counteract increased resistance to existing antimicrobial treatments and to combat currently untreatable or new emerging infectious diseases. We demonstrate that computational comparative genomics, together with experimental screening, can identify potential generic (i.e., conserved across multiple pathogen species and novel virulence-associated genes that may serve as targets for broad-spectrum countermeasures. Results Using phylogenetic profiles of protein clusters from completed microbial genome sequences, we identified seventeen protein candidates that are common to diverse human pathogens and absent or uncommon in non-pathogens. Mutants of 13 of these candidates were successfully generated in Yersinia pseudotuberculosis and the potential role of the proteins in virulence was assayed in an animal model. Six candidate proteins are suggested to be involved in the virulence of Y. pseudotuberculosis, none of which have previously been implicated in the virulence of Y. pseudotuberculosis and three have no record of involvement in the virulence of any bacteria. Conclusion This work demonstrates a strategy for the identification of potential virulence factors that are conserved across a number of human pathogenic bacterial species, confirming the usefulness of this tool.

  16. Effect of dentin on the antimicrobial efficacy of 3% sodium hypochlorite, 2% chlorhexidine, 17% ethylenediaminetetraacetic acid, and 18% etidronic acid on Candida albicans: An in vitro study

    Science.gov (United States)

    Karale, Rupali; Odedra, Kamal Maldebhai; Srirekha, A.; Champa, C.; Shetty, Ashwija; Pushpalatha, S; Sharma, Rini

    2016-01-01

    Aim: The aim of this study was to evaluate the effect of dentin on the antimicrobial efficacy of 3% sodium hypochlorite, 2% chlorhexidine, 17% EDTA and 18% etidronic acid against C. albicans. Methodology: Dentin powder was prepared from mandibular first premolar using electrical grinder and sterilized. 3% NaOCl, 2%CHX, 17% EDTA and 18% etidronic acid were tested against C. albicans in the presence and absence of dentin, in eppendorf tubes. Group 1 (presence of dentin):- 100ul dentin powder + 100ul C. albicans suspension + 100ul irrigating solution. Group 2 (absence of dentin):- 100ul C. albicans suspension+ 100ul irrigating solution. Control group:- 100ul C. albicans suspension.+ 100ul sterile saline Suspension was thoroughly mixed, submitted for serial dilution upto10-5 after 1 min and colony forming units were counted. Results: In group 2 (without dentin powder), 3% NaOCl and 2% CHX showed the lowest bacterial count compared to group 1 (with dentin powder). Dentin had a significant inhibitory effect on 3% NaOCl (P < 0.001) and 2% CHX (P<0.001). 17% EDTA showed lowest bacterial count in group 1 (with dentin powder) compared to group 2 (without dentin powder). 18% Etidronic acid showed similar bacterial counts in the both the groups. No reduction was observed in the control group. Conclusion: NaOCl & EDTA showed measurable antimicrobial effect even in the presence of dentin which can be promising in the reduction of C. albicans in root canal therapy. PMID:27656066

  17. An in vitro evaluation of the antimicrobial efficacy of Curcuma longa, Tachyspermum ammi, chlorhexidine gluconate, and calcium hydroxide on Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    Hemanshi Kumar

    2013-01-01

    Full Text Available Aim and Objectives: This in vitro study was designed to comparatively evaluate the antimicrobial efficacy of Curcuma longa (turmeric - T 1 -10%, T 2 -20%; Tachyspermum ammi (ajwain - A 1 -10%, A 2 -20%; chlorhexidine (CHX gluconate gel (hexigel - 1%; and calcium hydroxide (10% as intracanal medicaments against Enterococcus faecalis. Materials and Methods: Agar plates were prepared using brain-heart infusion (BHI agar. Cultures of E. faecalis were grown in BHI broth at 37°C. Well diffusion method was used to derive results. Plates were inoculated for 72 h at 37°C and microbial zones of inhibition were recorded. Statistical analysis was performed with repeated measures analysis of variance. Results: C. longa (T 2 -20% and CHX gluconate gel (hexigel - CHX-1% showed larger zones of microbial inhibition than C. longa (T 1 -10% that were statistically significant (P < 0.05 and were highly significant when compared to T. ammi (ajwain - A 1 and A 2 and calcium hydroxide. Conclusion: C. longa can be used as intracanal medicament in endodontic failure cases.

  18. An in vitro evaluation of the antimicrobial efficacy of Curcuma longa, Tachyspermum ammi, chlorhexidine gluconate, and calcium hydroxide on Enterococcus faecalis

    Science.gov (United States)

    Kumar, Hemanshi

    2013-01-01

    Aim and Objectives: This in vitro study was designed to comparatively evaluate the antimicrobial efficacy of Curcuma longa (turmeric – T1-10%, T2-20%); Tachyspermum ammi (ajwain – A1-10%, A2-20%); chlorhexidine (CHX) gluconate gel (hexigel – 1%); and calcium hydroxide (10%) as intracanal medicaments against Enterococcus faecalis. Materials and Methods: Agar plates were prepared using brain-heart infusion (BHI) agar. Cultures of E. faecalis were grown in BHI broth at 37°C. Well diffusion method was used to derive results. Plates were inoculated for 72 h at 37°C and microbial zones of inhibition were recorded. Statistical analysis was performed with repeated measures analysis of variance. Results: C. longa (T2-20%) and CHX gluconate gel (hexigel – CHX-1%) showed larger zones of microbial inhibition than C. longa (T1-10%) that were statistically significant (P < 0.05) and were highly significant when compared to T. ammi (ajwain – A1 and A2) and calcium hydroxide. Conclusion: C. longa can be used as intracanal medicament in endodontic failure cases. PMID:23716967

  19. IgE-mediated chlorhexidine allergy: a new occupational hazard?

    DEFF Research Database (Denmark)

    Nagendran, Vasantha; Wicking, Jennifer; Ekbote, Anjali;

    2009-01-01

    BACKGROUND: Chlorhexidine is an effective antimicrobial agent commonly used in UK hospitals, primarily for skin decontamination. Recent UK infection control guidelines recommend the use of 2% chlorhexidine solution in specific clinical settings, thus increasing chlorhexidine use by health care...... workers (HCWs). Chlorhexidine has been widely reported to cause IgE-mediated allergic reactions (from urticaria and angioedema to anaphylaxis) among patients undergoing surgery/invasive procedures. Despite its widespread use in health care settings, there are no reports of clinically confirmed...... occupational IgE-mediated chlorhexidine allergy. AIMS: To identify cases of chlorhexidine allergy among health care workers. METHODS: A questionnaire was distributed among HCWs in wards and operating theatres at a UK district general hospital to raise awareness of potential chlorhexidine allergy and to invite...

  20. Isolation and Characterization of a Broad Spectrum Bacteriocin from Bacillus amyloliquefaciens RX7

    Directory of Open Access Journals (Sweden)

    Kong Boon Lim

    2016-01-01

    Full Text Available We isolated a Bacillus strain, RX7, with inhibitory activity against Listeria monocytogenes from soil and identified it as Bacillus amyloliquefaciens based on 16S rRNA gene sequencing. The inhibitory activity was stable over a wide range of pH and was fully retained after 30 min at 80°C, after which it decreased gradually at higher temperatures. The activity was sensitive to the proteolytic action of α-chymotrypsin, proteinase-K, and trypsin, indicating its proteinaceous nature. This bacteriocin was active against a broad spectrum of bacteria and the fungus Candida albicans. Direct detection of antimicrobial activity on a sodium dodecyl sulfate-polyacrylamide gel suggested an apparent molecular mass of approximately 5 kDa. Ammonium sulfate precipitation and anion-exchange and gel permeation chromatography integrated with reverse phase-high-performance liquid chromatography were used for bacteriocin purification. Automated N-terminal Edman degradation of the purified RX7 bacteriocin recognized the first 15 amino acids as NH2-X-Ala-Trp-Tyr-Asp-Ile-Arg-Lys-Leu-Gly-Asn-Lys-Gly-Ala, where the letter X in the sequence indicates an unknown or nonstandard amino acid. Based on BLAST similarity search and multiple alignment analysis, the obtained partial sequence showed high homology with the two-peptide lantibiotic haloduracin (HalA1 from Bacillus halodurans, although at least two amino acids differed between the sequences. A time-kill study demonstrated a bactericidal mode of action of RX7 bacteriocin.

  1. Antimicrobial activity of sodium hypochlorite, chlorhexidine and MTAD® against Enterococcus faecalis biofilm on human dentin matrix in vitro

    Directory of Open Access Journals (Sweden)

    Cristiana Francescutti Murad

    2012-06-01

    Full Text Available Objective: This study evaluated the antimicrobial efficacy of 2.5% and 5.25% NaOCl, 2% gel and liquid CHX and MTAD against Enterococcus faecalis biofilms on human dentin. Material and methods: E. faecalis biofilms grown on dentin matrix of 216 root sections were submerged in test irrigants for 1, 5, 15 and 30 minutes. The antimicrobial activity of the test irrigants were assessed through CFU counts. Biofilm formation over the dentin surface was ensured by SEM analysis. Results: Results showed no statistic difference among CHX gel, 2.5% and 5.25% NaOCl. However, the CHX liquid and MTAD were less effective than 2.5% and 5.25% NaOCl. Only CHX liquid and MTAD had differences in its efficacy depending on the time. Conclusion: The most effective irrigants in eliminating E. faecalis biofilms were 2.5% and 5.25% NaOCl and 2% CHX gel, at all the tested time intervals, in comparison to CHX liquid and MTAD.

  2. Comparative Evaluation of Antimicrobial Activity of QMiX, 2.5% Sodium Hypochlorite, 2% Chlorhexidine, Guava Leaf Extract and Aloevera Extract Against Enterococcus faecalis and Candida albicans – An in-vitro Study

    Science.gov (United States)

    Krishnamma, Shoba; Peedikayil, Faizal; Aman, Shibu; Tomy, Nithya; Mariodan, Jithin Pulickal

    2016-01-01

    Introduction Debridement and disinfection of the root canal system is a critical step in endodontic treatment. Most of the irrigants presently used in the endodontic treatment can have an impact on the microbes surviving in the biofilm but none of them are able to do all of the required tasks. Researches are going on its full swing in order to produce an endodontic irrigant having ideal properties. Aim To compare the antimicrobial efficacy of different irrigants like QMiX, guava leaf extract, aloevera extract, 2.5% sodium hypochlorite and 2% chlorhexidine gluconate against Enterococcus faecalis and Candida albicans. Materials and Methods The antimicrobial activity was determined using agar diffusion test. The solutions were divided into five groups: Group I- QMiX, Group II- Guava leaf extract and Group III-Aloevera extract, Group IV–2.5% Sodium hypochlorite and Group V-2% Chlorhexidine. The zones of inhibition of growth were recorded. Results Statistical analysis was performed using one way ANOVA with post-hoc Tukey’s HSD. Values obtained were statistically analyzed (proot canal irrigants. PMID:27437354

  3. Control of Streptococcus sanguinis oral biofilm by novel chlorhexidine-chitosan mouthwash: an in vitro study

    Directory of Open Access Journals (Sweden)

    Bangalore V. Karthikeyan

    2013-04-01

    Full Text Available Objective: The most common prevalent infectious oral diseases in humans are caries and periodontal diseases, which are usually associated with dental plaque. The present in vitro study was designed to evaluate and compare the impact of new mouthwash formulation consisting of chlorhexidine (0.1% and bioadhesive chitosan (0.5% on dental plaque bacterial reduction, to that of chlorhexidine or chitosan alone. Methods: In this study, we analyzed the antimicrobial susceptibility of strains of Streptococcus sanguinis from clinical plaque samples to four different antimicrobial agents. Antimicrobial susceptibilities of the isolates to chlorhexidine (0.2%, chitosan (0.5%, chlorhexidine (0.1% plus chitosan (0.5% combination and saline were evaluated by disc diffusion method. Results: The zone of inhibition showed that chlorhexidine, chitosan and chlorhexidine-chitosan combination mouthwash exert an antimicrobial activity. A markedly higher and significant activity was obtained with chlorhexidine-chitosan combination mouthwash. On intergroup comparison there were statistically significant differences between all the tested solutions, except between chlorhexidine and chitosan mouthwash. Conclusion: Within the limitation of the present study, results showed that chlorhexidine-chitosan combination mouthrinse are superior in antimicrobial activity than chlorhexidine or chitosan alone. [J Exp Integr Med 2013; 3(2.000: 165-169

  4. Synthesis and antimicrobial evaluation of nitazoxanide-based analogues: identification of selective and broad spectrum activity.

    Science.gov (United States)

    Ballard, T Eric; Wang, Xia; Olekhnovich, Igor; Koerner, Taylor; Seymour, Craig; Salamoun, Joseph; Warthan, Michelle; Hoffman, Paul S; Macdonald, Timothy L

    2011-02-01

    A library composed of nitazoxanide-based analogues was synthesized and assayed for increased antibacterial efficacy against the pyruvate-ferredoxin oxidoreductase (PFOR) using microorganisms Helicobacter pylori, Campylobacter jejuni and Clostridium difficile. Derivatives were found to recapitulate and improve activity against these organisms and select analogues were tested for their ability to disrupt the PFOR enzyme directly. The library was also screened for activity against staphylococci and resulted in the identification of analogues capable of inhibiting both staphylococci and all PFOR organisms at low micromolar minimum inhibitory concentrations with low toxicity to human foreskin cells. PMID:21275058

  5. 洗必泰葡萄糖酸盐对感染根管细菌生物膜的实验研究%Evaluation of antimicrobial effect with chlorhexidine digluconate against endodontic bacterial biofilms.

    Institute of Scientific and Technical Information of China (English)

    杜田丰; 马净植; 刘得玺; 曹颖光

    2011-01-01

    Objective:The aim of this study was to evalute the antimicrobial effect with chlorhexidine against endodontic bacterial biofilms in vitro. Method: An aliquot of Enterococcus faecalis suspensions was inoculated in the sterile coverslip incubating anaerobically for 1 week to inform bacterial biofilm. The biofilms were exposed to 0.2 % or 5 %chlorhexidine digluconate (CHX) for 1 min and 5 min, and then analyzed by viability staining and confocal laser scanning microscope (CLSM). Result:Them was a more remarkable (P < 0.05) antimicrobial effect with both agents for 5 min then that for 1 min. 5 % CHX killed more (P < 0.05) biofilm bacteria than 0.2 % CHX by exposure of 1 min,but killed bacteria similar to (P > 0.05) 0.2 % CHX for 5 min. Conclusion: Chlorhexidine digluconate showed a promoted bactericidal activity against endodontic bacteria biofilms attributing to the concentration and the exposure time. In addition,using chlorhexidine digluconate alone could not be obtained a successful irrigating and disinfecting outcome.%目的:探讨洗必泰葡萄糖酸盐作为根管冲洗药物,对粪肠球菌生物膜的灭菌作用.方法:在无菌盖玻片上制备粪肠球菌生物膜,应用 0.2%和 5%洗必泰葡萄糖酸盐冲洗,分别作用 1 min 和 5 min,激光扫描共聚焦显微镜观察灭菌效果.结果:0.2%或 5%洗必泰葡萄糖酸盐的灭菌效果随作用时间的延长而增加(P0.05).结论:洗必泰葡萄糖酸盐具有明显的杀灭粪肠球菌生物膜的作用,其不同浓度和不同作用时间的灭菌效果不同,然而尚不能达到完美的根管冲洗消毒目的.

  6. Draft Genome Sequence of the Broad-Spectrum Xenobiotic Degrader Achromobacter xylosoxidans ADAF13

    OpenAIRE

    Iyer, Rupa; Damania, Ashish

    2016-01-01

    Achromobacter xylosoxidans ADAF13, isolated from farmland soil, possesses a large number of putative degradation genes and pathways that break down a wide variety of aromatic hydrocarbons, pesticides, endocrine disruptors, and other high-impact xenobiotics. These properties make this strain an excellent candidate for further development as a broad-spectrum bioremediation agent.

  7. Are Broad-Spectrum Fluoroquinolones More Likely To Cause Clostridium difficile-Associated Disease?

    OpenAIRE

    Dhalla, Irfan A.; Muhammad M Mamdani; Simor, Andrew E; Kopp, Alex; Rochon, Paula A; Juurlink, David N.

    2006-01-01

    Limited evidence suggests that broad-spectrum fluoroquinolones such as gatifloxacin and moxifloxacin are more likely to cause Clostridium difficile-associated disease than levofloxacin. In a population-based case-control study of outpatients prescribed fluoroquinolones, we found no increased risk of C. difficile-associated disease requiring hospitalization among patients prescribed gatifloxacin or moxifloxacin compared to levofloxacin.

  8. Draft Genome Sequence of the Broad-Spectrum Xenobiotic Degrader Achromobacter xylosoxidans ADAF13.

    Science.gov (United States)

    Iyer, Rupa; Damania, Ashish

    2016-01-01

    Achromobacter xylosoxidansADAF13, isolated from farmland soil, possesses a large number of putative degradation genes and pathways that break down a wide variety of aromatic hydrocarbons, pesticides, endocrine disruptors, and other high-impact xenobiotics. These properties make this strain an excellent candidate for further development as a broad-spectrum bioremediation agent. PMID:27081123

  9. Factors influencing success of clinical genome sequencing across a broad spectrum of disorders

    DEFF Research Database (Denmark)

    Taylor, Jenny C; Martin, Hilary C; Lise, Stefano;

    2015-01-01

    To assess factors influencing the success of whole-genome sequencing for mainstream clinical diagnosis, we sequenced 217 individuals from 156 independent cases or families across a broad spectrum of disorders in whom previous screening had identified no pathogenic variants. We quantified the numb...

  10. Silver Nanoparticles: Biosynthesis Using an ATCC Reference Strain of Pseudomonas aeruginosa and Activity as Broad Spectrum Clinical Antibacterial Agents

    Science.gov (United States)

    Quinteros, Melisa A.; Aiassa Martínez, Ivana M.; Dalmasso, Pablo R.; Páez, Paulina L.

    2016-01-01

    Currently, the biosynthesis of silver-based nanomaterials attracts enormous attention owing to the documented antimicrobial properties of these ones. This study reports the extracellular biosynthesis of silver nanoparticles (Ag-NPs) using a Pseudomonas aeruginosa strain from a reference culture collection. A greenish culture supernatant of P. aeruginosa incubated at 37°C with a silver nitrate solution for 24 h changed to a yellowish brown color, indicating the formation of Ag-NPs, which was confirmed by UV-vis spectroscopy, transmission electron microscopy, and X-ray diffraction. TEM analysis showed spherical and pseudospherical nanoparticles with a distributed size mainly between 25 and 45 nm, and the XRD pattern revealed the crystalline nature of Ag-NPs. Also it provides an evaluation of the antimicrobial activity of the biosynthesized Ag-NPs against human pathogenic and opportunistic microorganisms, namely, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Proteus mirabilis, Acinetobacter baumannii, Escherichia coli, P. aeruginosa, and Klebsiella pneumonia. Ag-NPs were found to be bioactive at picomolar concentration levels showing bactericidal effects against both Gram-positive and Gram-negative bacterial strains. This work demonstrates the first helpful use of biosynthesized Ag-NPs as broad spectrum bactericidal agents for clinical strains of pathogenic multidrug-resistant bacteria such as methicillin-resistant S. aureus, A. baumannii, and E. coli. In addition, these Ag-NPs showed negligible cytotoxic effect in human neutrophils suggesting low toxicity to the host. PMID:27340405

  11. Comparison of Antimicrobial Activity of Chlorhexidine, Coconut Oil, Probiotics, and Ketoconazole on Candida albicans Isolated in Children with Early Childhood Caries: An In Vitro Study.

    Science.gov (United States)

    Shino, Beena; Peedikayil, Faizal C; Jaiprakash, Shyamala R; Ahmed Bijapur, Gufran; Kottayi, Soni; Jose, Deepak

    2016-01-01

    Background. Early childhood caries (ECC) is associated with early colonisation and high levels of cariogenic microorganisms. With C. albicans being one of those, there is a need to determine the effectiveness of various chemotherapeutic agents against it. The study is aimed at isolating Candida species in children with ECC and at studying the antifungal effect of coconut oil, probiotics, Lactobacillus, and 0.2% chlorhexidine on C. albicans in comparison with ketoconazole. Materials and Methods. Samples were collected using sterile cotton swabs, swabbed on the tooth surfaces from children with ECC of 3 to 6 yrs and streaked on Sabouraud dextrose agar (HI Media) plates and incubated in a 5% CO2 enriched atmosphere at 37°C for 24 hours. Candida was isolated and its susceptibility to probiotics, chlorhexidine, ketoconazole, and coconut oil was determined using Disc Diffusion method. Results. The mean zone of inhibition for chlorhexidine was 21.8 mm, whereas for coconut oil it was 16.8 mm, for probiotics it was 13.5 mm, and for ketoconazole it was 22.3 mm. The difference between the groups was not statistically significant (Chi-square value 7.42, P value 0.06). Conclusion. Chlorhexidine and coconut oil have shown significant antifungal activity which is comparable with ketoconazole.

  12. Allergy to Chlorhexidine.

    Science.gov (United States)

    Pemberton, Michael N

    2016-04-01

    Chlorhexidine is an effective antiseptic which is widely used in dentistry. Over recent years, it has also been used in other healthcare products as well as in cosmetics. Anaphylaxis to chlorhexidine has been increasingly reported throughout the world, including two incidents in the UK where chlorhexidine-containing mouthwash had been used to wash tooth sockets following recent tooth extraction. Chlorhexidine is under-recognized as a cause of anaphylaxis and dentists should be aware of its potential for serious adverse effects. Dentists need to consider whether the washing out of a tooth socket with chlorhexidine solution should be avoided in the treatment of established dry socket. On current evidence the potential risks of using chlorhexidine as irrigation solution for treating an established dry socket appears to outweigh any known benefit. CPD/Clinical Relevance: Chlorhexidine has the potential to cause anaphylaxis in the dental surgery. PMID:27439274

  13. Broad-Spectrum Antibiotic Treatment and Subsequent Childhood Type 1 Diabetes: A Nationwide Danish Cohort Study

    Science.gov (United States)

    Bergholt, Thomas; Bouaziz, Olivier; Arpi, Magnus; Eriksson, Frank; Rasmussen, Steen; Keiding, Niels; Løkkegaard, Ellen C.

    2016-01-01

    Background Studies link antibiotic treatment and delivery by cesarean section with increased risk of chronic diseases through changes of the gut-microbiota. We aimed to evaluate the association of broad-spectrum antibiotic treatment during the first two years of life with subsequent onset of childhood type 1 diabetes and the potential effect-modification by mode of delivery. Materials and Methods A Danish nationwide cohort study including all singletons born during 1997–2010. End of follow-up by December 2012. Four national registers provided information on antibiotic redemptions, outcome and confounders. Redemptions of antibiotic prescriptions during the first two years of life was classified into narrow-spectrum or broad-spectrum antibiotics. Children were followed from age two to fourteen, both inclusive. The risk of type 1 diabetes with onset before the age of 15 years was assessed by Cox regression. A total of 858,201 singletons contributed 5,906,069 person-years, during which 1,503 children developed type 1 diabetes. Results Redemption of broad-spectrum antibiotics during the first two years of life was associated with an increased rate of type 1 diabetes during the following 13 years of life (HR 1.13; 95% CI 1.02 to 1.25), however, the rate was modified by mode of delivery. Broad-spectrum antibiotics were associated with an increased rate of type 1 diabetes in children delivered by either intrapartum cesarean section (HR 1.70; 95% CI 1.15 to 2.51) or prelabor cesarean section (HR 1.63; 95% CI 1.11 to 2.39), but not in vaginally delivered children. Number needed to harm was 433 and 562, respectively. The association with broad-spectrum antibiotics was not modified by parity, genetic predisposition or maternal redemption of antibiotics during pregnancy or lactation. Conclusions Redemption of broad-spectrum antibiotics during infancy is associated with an increased risk of childhood type 1 diabetes in children delivered by cesarean section. PMID:27560963

  14. Squalamine as a broad-spectrum systemic antiviral agent with therapeutic potential.

    Science.gov (United States)

    Zasloff, Michael; Adams, A Paige; Beckerman, Bernard; Campbell, Ann; Han, Ziying; Luijten, Erik; Meza, Isaura; Julander, Justin; Mishra, Abhijit; Qu, Wei; Taylor, John M; Weaver, Scott C; Wong, Gerard C L

    2011-09-20

    Antiviral compounds that increase the resistance of host tissues represent an attractive class of therapeutic. Here, we show that squalamine, a compound previously isolated from the tissues of the dogfish shark (Squalus acanthias) and the sea lamprey (Petromyzon marinus), exhibits broad-spectrum antiviral activity against human pathogens, which were studied in vitro as well as in vivo. Both RNA- and DNA-enveloped viruses are shown to be susceptible. The proposed mechanism involves the capacity of squalamine, a cationic amphipathic sterol, to neutralize the negative electrostatic surface charge of intracellular membranes in a way that renders the cell less effective in supporting viral replication. Because squalamine can be readily synthesized and has a known safety profile in man, we believe its potential as a broad-spectrum human antiviral agent should be explored. PMID:21930925

  15. Artificial TALE as a Convenient Protein Platform for Engineering Broad-Spectrum Resistance to Begomoviruses.

    Science.gov (United States)

    Cheng, Xiaofei; Li, Fangfang; Cai, Jianyu; Chen, Wei; Zhao, Nan; Sun, Yuqiang; Guo, Yushuang; Yang, Xiuling; Wu, Xiaoyun

    2015-08-01

    Transcription activator-like effectors (TALEs) are a class of sequence-specific DNA-binding proteins that utilize a simple and predictable modality to recognize target DNA. This unique characteristic allows for the rapid assembly of artificial TALEs, with high DNA binding specificity, to any target DNA sequences for the creation of customizable sequence-specific nucleases used in genome engineering. Here, we report the use of an artificial TALE protein as a convenient platform for designing broad-spectrum resistance to begomoviruses, one of the most destructive plant virus groups, which cause tremendous losses worldwide. We showed that artificial TALEs, which were assembled based on conserved sequence motifs within begomovirus genomes, could confer partial resistance in transgenic Nicotiana benthamiana to all three begomoviruses tested. Furthermore, the resistance was maintained even in the presence of their betasatellite. These results shed new light on the development of broad-spectrum resistance against DNA viruses, such as begomoviruses. PMID:26308041

  16. Broad-Spectrum Antibiotic Treatment and Subsequent Childhood Type 1 Diabetes

    DEFF Research Database (Denmark)

    Clausen, Tine D; Bergholt, Thomas; Bouaziz, Olivier;

    2016-01-01

    of childhood type 1 diabetes and the potential effect-modification by mode of delivery. MATERIALS AND METHODS: A Danish nationwide cohort study including all singletons born during 1997-2010. End of follow-up by December 2012. Four national registers provided information on antibiotic redemptions, outcome...... and confounders. Redemptions of antibiotic prescriptions during the first two years of life was classified into narrow-spectrum or broad-spectrum antibiotics. Children were followed from age two to fourteen, both inclusive. The risk of type 1 diabetes with onset before the age of 15 years was assessed by Cox...... regression. A total of 858,201 singletons contributed 5,906,069 person-years, during which 1,503 children developed type 1 diabetes. RESULTS: Redemption of broad-spectrum antibiotics during the first two years of life was associated with an increased rate of type 1 diabetes during the following 13 years...

  17. The Discussion about Truth Viewpoint and its Significance on the View of Broad-Spectrum Philosophy

    Directory of Open Access Journals (Sweden)

    Facheng Shang

    2012-11-01

    Full Text Available In this study, we have a discussion about truth viewpoint and its significance on the view of Broad-spectrum Philosophy, which inherit and develop the truth of Marxist philosophy Broad-spectrum. Philosophy provides a unique perspective; it introduces the concept of observocontrol mode, which regards the truth as an image in the equivalence class. By changing the observocontrol mode, it reveals “Multilobe” of the truth of the same objective. To answer the question on "how to test the truth", it constructs the procedures and criteria to knowledge the truth. These researches have an important revelation on the enrichment and development of the study of Marxism truth theory.

  18. Synthesis and Broad-Spectrum Antiviral Activity of Some Novel Benzo-Heterocyclic Amine Compounds

    Directory of Open Access Journals (Sweden)

    Da-Jun Zhang

    2014-01-01

    Full Text Available A series of novel unsaturated five-membered benzo-heterocyclic amine derivatives were synthesized and assayed to determine their in vitro broad-spectrum antiviral activities. The biological results showed that most of our synthesized compounds exhibited potent broad-spectrum antiviral activity. Notably, compounds 3f (IC50 = 3.21–5.06 μM and 3g (IC50 = 0.71–34.87 μM showed potent activity towards both RNA viruses (influenza A, HCV and Cox B3 virus and a DNA virus (HBV at low micromolar concentrations. An SAR study showed that electron-withdrawing substituents located on the aromatic or heteroaromatic ring favored antiviral activity towards RNA viruses.

  19. Squalamine as a broad-spectrum systemic antiviral agent with therapeutic potential

    OpenAIRE

    Zasloff, Michael; Adams, A. Paige; Beckerman, Bernard; Campbell, Ann; Han, Ziying; Luijten, Erik; Meza, Isaura; Julander, Justin; Mishra, Abhijit; Qu, Wei; Taylor, John M; Scott C Weaver; Wong, Gerard C. L.

    2011-01-01

    Antiviral compounds that increase the resistance of host tissues represent an attractive class of therapeutic. Here, we show that squalamine, a compound previously isolated from the tissues of the dogfish shark (Squalus acanthias) and the sea lamprey (Petromyzon marinus), exhibits broad-spectrum antiviral activity against human pathogens, which were studied in vitro as well as in vivo. Both RNA- and DNA-enveloped viruses are shown to be susceptible. The proposed mechanism involves the capacit...

  20. Broad-spectrum respiratory tract pathogen identification using resequencing DNA microarrays

    OpenAIRE

    Lin, Baochuan; Wang, Zheng; Vora, Gary J.; Jennifer A. Thornton; Schnur, Joel M.; Thach, Dzung C.; Blaney, Kate M.; Ligler, Adam G.; Malanoski, Anthony P.; Santiago, Jose; Walter, Elizabeth A.; Agan, Brian K.; Metzgar, David; Seto, Donald; Daum, Luke T.

    2006-01-01

    The exponential growth of pathogen nucleic acid sequences available in public domain databases has invited their direct use in pathogen detection, identification, and surveillance strategies. DNA microarray technology has offered the potential for the direct DNA sequence analysis of a broad spectrum of pathogens of interest. However, to achieve the practical attainment of this potential, numerous technical issues, especially nucleic acid amplification, probe specificity, and interpretation st...

  1. Broad-spectrum transgenic resistance against distinct tospovirus species at the genus level.

    Directory of Open Access Journals (Sweden)

    Jui-Chu Peng

    Full Text Available Thrips-borne tospoviruses cause severe damage to crops worldwide. In this investigation, tobacco lines transgenic for individual WLm constructs containing the conserved motifs of the L RNA-encoded RNA-dependent RNA polymerase (L gene of Watermelon silver mottle virus (WSMoV were generated by Agrobacterium-mediated transformation. The WLm constructs included: (i translatable WLm in a sense orientation; (ii untranslatable WLmt with two stop codons; (iii untranslatable WLmts with stop codons and a frame-shift; (iv untranslatable antisense WLmA; and (v WLmhp with an untranslatable inverted repeat of WLm containing the tospoviral S RNA 3'-terminal consensus sequence (5'-ATTGCTCT-3' and an NcoI site as a linker to generate a double-stranded hairpin transcript. A total of 46.7-70.0% transgenic tobacco lines derived from individual constructs showed resistance to the homologous WSMoV; 35.7-100% plants of these different WSMoV-resistant lines exhibited broad-spectrum resistance against four other serologically unrelated tospoviruses Tomato spotted wilt virus, Groundnut yellow spot virus, Impatiens necrotic spot virus and Groundnut chlorotic fan-spot virus. The selected transgenic tobacco lines also exhibited broad-spectrum resistance against five additional tospoviruses from WSMoV and Iris yellow spot virus clades, but not against RNA viruses from other genera. Northern analyses indicated that the broad-spectrum resistance is mediated by RNA silencing. To validate the L conserved region resistance in vegetable crops, the constructs were also used to generate transgenic tomato lines, which also showed effective resistance against WSMoV and other tospoviruses. Thus, our approach of using the conserved motifs of tospoviral L gene as a transgene generates broad-spectrum resistance against tospoviruses at the genus level.

  2. The broad-spectrum antiviral compound ST-669 restricts chlamydial inclusion development and bacterial growth and localizes to host cell lipid droplets within treated cells.

    Science.gov (United States)

    Sandoz, Kelsi M; Valiant, William G; Eriksen, Steven G; Hruby, Dennis E; Allen, Robert D; Rockey, Daniel D

    2014-07-01

    Novel broad-spectrum antimicrobials are a critical component of a strategy for combating antibiotic-resistant pathogens. In this study, we explored the activity of the broad-spectrum antiviral compound ST-669 for activity against different intracellular bacteria and began a characterization of its mechanism of antimicrobial action. ST-669 inhibits the growth of three different species of chlamydia and the intracellular bacterium Coxiella burnetii in Vero and HeLa cells but not in McCoy (murine) cells. The antichlamydial and anti-C. burnetii activity spectrum was consistent with those observed for tested viruses, suggesting a common mechanism of action. Cycloheximide treatment in the presence of ST-669 abrogated the inhibitory effect, demonstrating that eukaryotic protein synthesis is required for tested activity. Immunofluorescence microscopy demonstrated that different chlamydiae grow atypically in the presence of ST-669, in a manner that suggests the compound affects inclusion formation and organization. Microscopic analysis of cells treated with a fluorescent derivative of ST-669 demonstrated that the compound localized to host cell lipid droplets but not to other organelles or the host cytosol. These results demonstrate that ST-669 affects intracellular growth in a host-cell-dependent manner and interrupts proper development of chlamydial inclusions, possibly through a lipid droplet-dependent process. PMID:24777097

  3. Choline and Geranate Deep Eutectic Solvent as a Broad-Spectrum Antiseptic Agent for Preventive and Therapeutic Applications.

    Science.gov (United States)

    Zakrewsky, Michael; Banerjee, Amrita; Apte, Sanjana; Kern, Theresa L; Jones, Mattie R; Sesto, Rico E Del; Koppisch, Andrew T; Fox, David T; Mitragotri, Samir

    2016-06-01

    Antiseptic agents are the primary arsenal to disinfect skin and prevent pathogens spreading within the host as well as into the surroundings; however the Food and Drug Administration published a report in 2015 requiring additional validation of nearly all current antiseptic agents before their continued use can be allowed. This vulnerable position calls for urgent identification of novel antiseptic agents. Recently, the ability of a deep eutectic, Choline And Geranate (CAGE), to treat biofilms of Pseudomonas aeruginosa and Salmonella enterica was demonstrated. Here it is reported that CAGE exhibits broad-spectrum antimicrobial activity against a number of drug-resistant bacteria, fungi, and viruses including clinical isolates of Mycobacterium tuberculosis, Staphylococcus aureus, and Candida albicans as well as laboratory strains of Herpes Simplex Virus. Studies in human keratinocytes and mice show that CAGE affords negligible local or systemic toxicity, and an ≈180-14 000-fold improved efficacy/toxicity ratio over currently used antiseptic agents. Further, CAGE penetrates deep into the dermis and treats pathogens located in deep skin layers as confirmed by the ability of CAGE in vivo to treat Propionibacterium acnes infection. In combination, the results clearly demonstrate CAGE holds promise as a transformative platform antiseptic agent for preventive as well as therapeutic applications. PMID:26959835

  4. Broad spectrum antiviral activity of favipiravir (T-705: protection from highly lethal inhalational Rift Valley Fever.

    Directory of Open Access Journals (Sweden)

    Amy L Caroline

    2014-04-01

    Full Text Available BACKGROUND: Development of antiviral drugs that have broad-spectrum activity against a number of viral infections would be of significant benefit. Due to the evolution of resistance to currently licensed antiviral drugs, development of novel anti-influenza drugs is in progress, including Favipiravir (T-705, which is currently in human clinical trials. T-705 displays broad-spectrum in vitro activity against a number of viruses, including Rift Valley Fever virus (RVFV. RVF is an important neglected tropical disease that causes human, agricultural, and economic losses in endemic regions. RVF has the capacity to emerge in new locations and also presents a potential bioterrorism threat. In the current study, the in vivo efficacy of T-705 was evaluated in Wistar-Furth rats infected with the virulent ZH501 strain of RVFV by the aerosol route. METHODOLOGY/PRINCIPAL FINDINGS: Wistar-Furth rats are highly susceptible to a rapidly lethal disease after parenteral or inhalational exposure to the pathogenic ZH501 strain of RVFV. In the current study, two experiments were performed: a dose-determination study and a delayed-treatment study. In both experiments, all untreated control rats succumbed to disease. Out of 72 total rats infected with RVFV and treated with T-705, only 6 succumbed to disease. The remaining 66 rats (92% survived lethal infection with no significant weight loss or fever. The 6 treated rats that succumbed survived significantly longer before succumbing to encephalitic disease. CONCLUSIONS/SIGNIFICANCE: Currently, there are no licensed antiviral drugs for treating RVF. Here, T-705 showed remarkable efficacy in a highly lethal rat model of Rift Valley Fever, even when given up to 48 hours post-infection. This is the first study to show protection of rats infected with the pathogenic ZH501 strain of RVFV. Our data suggest that T-705 has potential to be a broad-spectrum antiviral drug.

  5. An atypical kinase under balancing selection confers broad-spectrum disease resistance in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Carine Huard-Chauveau

    Full Text Available The failure of gene-for-gene resistance traits to provide durable and broad-spectrum resistance in an agricultural context has led to the search for genes underlying quantitative resistance in plants. Such genes have been identified in only a few cases, all for fungal or nematode resistance, and encode diverse molecular functions. However, an understanding of the molecular mechanisms of quantitative resistance variation to other enemies and the associated evolutionary forces shaping this variation remain largely unknown. We report the identification, map-based cloning and functional validation of QRX3 (RKS1, Resistance related KinaSe 1, conferring broad-spectrum resistance to Xanthomonas campestris (Xc, a devastating worldwide bacterial vascular pathogen of crucifers. RKS1 encodes an atypical kinase that mediates a quantitative resistance mechanism in plants by restricting bacterial spread from the infection site. Nested Genome-Wide Association mapping revealed a major locus corresponding to an allelic series at RKS1 at the species level. An association between variation in resistance and RKS1 transcription was found using various transgenic lines as well as in natural accessions, suggesting that regulation of RKS1 expression is a major component of quantitative resistance to Xc. The co-existence of long lived RKS1 haplotypes in A. thaliana is shared with a variety of genes involved in pathogen recognition, suggesting common selective pressures. The identification of RKS1 constitutes a starting point for deciphering the mechanisms underlying broad spectrum quantitative disease resistance that is effective against a devastating and vascular crop pathogen. Because putative RKS1 orthologous have been found in other Brassica species, RKS1 provides an exciting opportunity for plant breeders to improve resistance to black rot in crops.

  6. Chlorhexidine in cosmetic products

    DEFF Research Database (Denmark)

    Opstrup, Morten Schjørring; Johansen, Jeanne Duus; Bossi, Rossana;

    2015-01-01

    and April 2013, we checked for chlorhexidine in cosmetic products in 14 supermarkets, one hairdressing salon and one beauty and retail store in Copenhagen, Denmark by reading the ingredient labels. The chlorhexidine concentration was measured in 10 selected products by high-performance liquid chromatography...

  7. Broad-spectrum sun-protective action of Porphyra-334 derived from Porphyra vietnamensis

    OpenAIRE

    Saurabh Bhatia; Sharma, K.; Namdeo, Ajay G.; B B Chaugule; Kavale, M.; Nanda, S

    2010-01-01

    There are enormous UV-protective compounds present in the current world market, out of which 98% give protection against UV-B range and the remaining 2% are potent against far UV-A range only. Furthermore, these synthetic compounds have various problems related to photo-stability and cross-stability. There is a vital need of sunscreen agents that will remain stable for prolonged periods and provide broad-spectrum protection against harmful UV range. The Indian Ocean contains large amounts of ...

  8. To comparatively evaluate the antimicrobial efficacy of chlorhexidine, nisin and linezolid as an intracanal medicament on Enterococcus faecalis: An in vitro study

    Directory of Open Access Journals (Sweden)

    Geethu Somanath

    2015-01-01

    Results: In group Nisin, the mean CFU was 10.6250 at 24 hrs, 6.6250 at 72 hrs and 6.2500 after 1 week respectively (statistically significant. In group Chlorhexidine, mean CFU was found to be the lowest of 10.5000 at 24 hrs, with further gradual increase to 13.7500 at 72 hrs and further increase to 15.8750 by 1 week. Similarly, in group linezolid , the mean CFU was found to decrease from 49.0000 at 24 hrs to 29.8750 at 72hrs and then increase to 34.8750 in 1 week

  9. Antimicrobial efficacy of external fixator pins coated with a lipid stabilized hydroxyapatite/chlorhexidine complex to prevent pin tract infection in a goat model.

    Energy Technology Data Exchange (ETDEWEB)

    Dejong, E. Schuyler; Deberardino, T. M.; Brooks, D. E.; Nelson, B. J.; Campbell, Allison A.; Bottoni, Craig R.; Pusateri, A. E.; Walton, R. S.; Guymon, C. H.; Mcmanus, Albert T.

    2001-06-01

    Background: Pin tract infection is a common complication of external fixation. An antiinfective external fixator pin might help to reduce the incidence of pin tract infection and improve pin fixation. Methods: Stainless steel and titanium external fixator pins, with and without a lipid stabilized hydroxyapatite/chlorhexidine coating, were evaluated in a goat model. Two pins contaminated with an identifiable Staphylococcus aureus strain were inserted into each tibia of 12 goats. The pin sites were examined daily. On day 14, the animals were killed, and the pin tips cultured. Insertion and extraction torques were measured. Results: Infection developed in 100% of uncoated pins, whereas coated pins demonstrated 4.2% infected, 12.5% colonized, and the remainder, 83.3%, had no growth (p < 0.01). Pin coating decreased the percent loss of fixation torque over uncoated pins (p = 0.04). Conclusion: These results demonstrate that the lipid stabilized hydroxyapatite/chlorhexidine coating was successful in decreasing infection and improving fixation of external fixator pins.

  10. Broad-spectrum micronutrient treatment for attention-deficit/hyperactivity disorder: rationale and evidence to date.

    Science.gov (United States)

    Rucklidge, Julia J; Kaplan, Bonnie J

    2014-09-01

    Attention-deficit/hyperactivity disorder (ADHD) is a chronic psychiatric illness, which often co-occurs with other common psychiatric problems. Although empirical evidence supports the short-term efficacy of pharmacological and behavioural treatments, families often search for alternative treatment methods because of concerns about side effects and safety, cost and access, as well as fears about long-term exposure to psychotropic medications. This review presents the published evidence on use of broad-spectrum micronutrients to treat ADHD symptoms. This approach makes physiological sense in that nutrients are required for many critical biochemical reactions to occur, ranging from manufacturing neurotransmitters, to providing the mitochondria with essential nutrients for energy production, to assisting the gut to heal from inflammation. Multi-nutrient treatment approaches are an intriguing yet under-researched area; all but one of the trials conducted in the last decade have shown benefit for the treatment of ADHD symptoms, and the one negative trial likely used doses too low to effect change. However, the methodologies have varied widely from case-controlled studies to open-label trials to one randomized controlled trial. Sample sizes have typically been modest, although the effect sizes have tended to be medium to large. What is required now is replication, as well as investigation into the optimal ingredient range and optimal doses of nutrients. We discuss the proven and potential benefits of the broad-spectrum nutrient approach, considering the heterogeneous nature of ADHD. PMID:25056569

  11. Nanomedicine for Infectious Disease Applications: Innovation towards Broad-Spectrum Treatment of Viral Infections.

    Science.gov (United States)

    Jackman, Joshua A; Lee, Jaywon; Cho, Nam-Joon

    2016-03-01

    Nanomedicine enables unique diagnostic and therapeutic capabilities to tackle problems in clinical medicine. As multifunctional agents with programmable properties, nanomedicines are poised to revolutionize treatment strategies. This promise is especially evident for infectious disease applications, for which the continual emergence, re-emergence, and evolution of pathogens has proven difficult to counter by conventional approaches. Herein, a conceptual framework is presented that envisions possible routes for the development of nanomedicines as superior broad-spectrum antiviral agents against enveloped viruses. With lipid membranes playing a critical role in the life cycle of medically important enveloped viruses including HIV, influenza, and Ebola, cellular and viral membrane interfaces are ideal elements to incorporate into broad-spectrum antiviral strategies. Examples are presented that demonstrate how nanomedicine strategies inspired by lipid membranes enable a wide range of targeting opportunities to gain control of critical stages in the virus life cycle through either direct or indirect approaches involving membrane interfaces. The capabilities can be realized by enabling new inhibitory functions or improving the function of existing drugs through nanotechnology-enabled solutions. With these exciting opportunities, due attention is also given to the clinical translation of nanomedicines for infectious disease applications, especially as pharmaceutical drug-discovery pipelines demand new routes of innovation.

  12. Nanomedicine for Infectious Disease Applications: Innovation towards Broad-Spectrum Treatment of Viral Infections.

    Science.gov (United States)

    Jackman, Joshua A; Lee, Jaywon; Cho, Nam-Joon

    2016-03-01

    Nanomedicine enables unique diagnostic and therapeutic capabilities to tackle problems in clinical medicine. As multifunctional agents with programmable properties, nanomedicines are poised to revolutionize treatment strategies. This promise is especially evident for infectious disease applications, for which the continual emergence, re-emergence, and evolution of pathogens has proven difficult to counter by conventional approaches. Herein, a conceptual framework is presented that envisions possible routes for the development of nanomedicines as superior broad-spectrum antiviral agents against enveloped viruses. With lipid membranes playing a critical role in the life cycle of medically important enveloped viruses including HIV, influenza, and Ebola, cellular and viral membrane interfaces are ideal elements to incorporate into broad-spectrum antiviral strategies. Examples are presented that demonstrate how nanomedicine strategies inspired by lipid membranes enable a wide range of targeting opportunities to gain control of critical stages in the virus life cycle through either direct or indirect approaches involving membrane interfaces. The capabilities can be realized by enabling new inhibitory functions or improving the function of existing drugs through nanotechnology-enabled solutions. With these exciting opportunities, due attention is also given to the clinical translation of nanomedicines for infectious disease applications, especially as pharmaceutical drug-discovery pipelines demand new routes of innovation. PMID:26551316

  13. Should surgeons scrub with chlorhexidine or iodine prior to surgery?

    Science.gov (United States)

    Jarral, Omar A; McCormack, David J; Ibrahim, Sammra; Shipolini, Alex R

    2011-06-01

    A best evidence topic was written according to a structured protocol. The question addressed was whether chlorhexidine gluconate is equivalent or superior to the use of povidone-iodine during surgical hand scrub. A total of 593 papers were found using the reported searches of which eight represented the best evidence to answer the clinical question. The authors, date, journal, study type, population, main outcome measures and results are tabulated. We conclude that whilst both chlorhexidine and povidone-iodine reduce bacterial count after scrubbing, the effect of chlorhexidine is both more profound and longer lasting. The studies found analysed the difference in reduction in colony forming units or bacterial count following surgical scrub in order to conclude that chlorhexidine was superior. Four studies went further to analyse cumulative and residual activity by testing for bacterial reduction after using a scrub solution for a number of days, an area in which chlorhexidine showed consistent advantages over povidone-iodine. These findings are given more credibility by the clinical finding of a recent meta-analysis of over 5000 patients in which chlorhexidine as an antiseptic skin preparation was associated with significantly reduced surgical site infection (SSI) in clean-contaminated surgery. Despite this, there is no evidence suggesting the use of chlorhexidine during hand scrub reduces SSI, which perhaps explains why guidelines from the World Health Organization, the Centers for Disease Control and Prevention and the Association for Perioperative Practice do not recommend one specific antimicrobial over another for hand scrub.

  14. Antimicrobial Activity of Chlorhexidine, Peracetic acid/ Peroxide hydrogen and Alcohol based compound on Isolated Bacteria in Madani Heart Hospital, Tabriz, Azerbaijan, Iran

    Directory of Open Access Journals (Sweden)

    Reza Ghotaslou

    2012-06-01

    Full Text Available Purpose: The aim of present study was to investigate the effect of chemical agents on the clinical isolates in Madani Heart Hospital, Tabriz, Iran. Methods: The minimum bactericide concentration (MBC of disinfectants including chlorhexidine (Fort, peracetic acid (Micro and an alcohol based compound (Deconex on selected bacteria at various dilutions were determined by the standard suspension technique. Results: MBC of Micro, Fort and Deconex were 2-128 mg/L, 2-64 mg/L and 4 - 32 mg/L, respectively. The Gram negative bacteria were more resistance to disinfectant relation to Gram positive bacteria. Conclusion: The results showed that these agents are able to eradicate the bacteria and they can be used lonely.

  15. Multilayer nanoparticle arrays for broad spectrum absorption enhancement in thin film solar cells

    CERN Document Server

    Krishnan, Aravind; Krishna, Siva Rama; Khan, Mohammed Zafar Ali

    2013-01-01

    In this paper, we present a theoretical study on the absorption efficiency enhancement of a thin film amorphous Silicon (a-Si) photovoltaic cell over a broad spectrum of wavelengths using multiple nanoparticle arrays. The light absorption efficiency is enhanced in the lower wavelengths by a nanoparticle array on the surface and in the higher wavelengths by another nanoparticle array embedded in the active region. The efficiency at intermediate wavelengths is enhanced by the constructive interference of plasmon coupled light. We optimize this design by tuning the radius of particles in both arrays, the period of the array and the distance between the two arrays. The optimization results in 61.44% increase in total quantum efficiency for a 500 nm thick a-Si substrate.

  16. Integrative therapies in cancer: modulating a broad spectrum of targets for cancer management.

    Science.gov (United States)

    Block, Keith I; Block, Penny B; Gyllenhaal, Charlotte

    2015-03-01

    Integrative medicine is an approach to health and healing that "makes use of all appropriate therapeutic approaches, health care professionals, and disciplines to achieve optimal health and healing." A comprehensive integrative medicine intervention for cancer patients typically includes nutritional counseling, biobehavioral strategies, and promotion of physical activity, as well as dietary supplements including herbs, nutraceuticals, and phytochemicals. A broad-spectrum intervention of this type may contribute uniquely to improvement in cancer outcomes through its impact on a wide variety of relevant molecular targets, including effects on multiple cancer hallmarks. Hallmarks that may be particularly affected include genetic instability, tumor-promoting inflammation, deregulated metabolism, and immune system evasion. Because of their susceptibility to manipulation by diet, exercise, and supplementation, these may be characterized as metabolic hallmarks. Research on the use of comprehensive integrative approaches can contribute to the development of systems of multitargeted treatment regimens and would help clarify the combined effect of these approaches on cancer outcomes. PMID:25601968

  17. Broad spectrum moderators and advanced reflector filters using 208Pb

    DEFF Research Database (Denmark)

    Schönfeldt, Troels; Batkov, K.; Klinkby, Esben Bryndt;

    2015-01-01

    Cold and thermal neutrons used in neutrons scattering experiments are produced in nuclear reactors and spallation sources. The neutrons are cooled to thermal or cold temperatures in thermal and cold moderators, respectively. The present study shows that it is possible to exploit the poor...... thermalizing property of 208Pb to design a broad spectrum moderator, i.e. a moderator which emits thermal and cold neutrons from the same position. Using 208Pb as a reflector filter material is shown to be slightly less efficient than a conventional beryllium reflector filter. However, when surrounding the...... reflector filter by a cold moderator it is possible to regain the neutrons with wavelengths below the Bragg edge, which are suppressed in the beryllium reflector filter. In both the beryllium and lead case surrounding the reflector filter with a cold moderator increases the cold brightness significantly...

  18. Analysis of mobile health applications for a broad spectrum of consumers: a user experience approach.

    Science.gov (United States)

    García-Gómez, Juan M; de la Torre-Díez, Isabel; Vicente, Javier; Robles, Montserrat; López-Coronado, Miguel; Rodrigues, Joel J

    2014-03-01

    Mobile health (m-health) apps can bring health prevention and promotion to the general population. The main purpose of this article is to analyze different m-health apps for a broad spectrum of consumers by means of three different experiences. This goal was defined following the strategic documents generated by the main prospective observatories of Information and Communications Technology for health. After a general exploration of the app markets, we analyze the entries of three specific themes focused in this article: type 2 diabetes, obesity, and breast-feeding. The user experiences reported in this study mostly cover the segments of (1) chronically monitored consumers through a Web mobile app for predicting type 2 diabetes (Diab_Alert app), (2) information seekers through a mobile app for maternity (Lactation app) and partially (3) the motivated healthy consumers through a mobile app for a dietetic monitoring and assessment (SapoFit app). These apps were developed by the authors of this work.

  19. Chlorhexidine-calcium phosphate nanoparticles - Polymer mixer based wound healing cream and their applications.

    Science.gov (United States)

    Viswanathan, Kaliyaperumal; Monisha, P; Srinivasan, M; Swathi, D; Raman, M; Dhinakar Raj, G

    2016-10-01

    In this work, we developed a wound healing cream composed of two different polymers, namely chitosan and gelatin with chlorhexidine along with calcium phosphate nanoparticles. The physicochemical properties of the prepared cream were investigated based on SEM, EDX, Raman, FTIR and the results indicated that the cream contained gelatin, chitosan, calcium phosphate nanoparticles and chlorhexidine. The maximum swelling ratio studies indicated that the ratio was around of 52±2.2 at pH7.4 and the value was increased in acidic and alkaline pH. The antimicrobial activity was tested against bacteria and the results indicated that, both chlorhexidine and the hybrid cream devoid of chlorhexidine exhibited antimicrobial activity but the chlorhexidine impregnated cream showed three fold higher antimicrobial activity than without chlorhexidine. In vivo wound healing promoting activities of hybrid cream containing 0.4mg/L chlorhexidine were evaluated on surgically induced dermal wounds in mice. The results indicated that the cream with incorporated chlorhexidine significantly enhanced healing compared with the control samples. For the field validations, the veterinary clinical animals were treated with the cream and showed enhanced healing capacity. In conclusion, a simple and efficient method for design of a novel wound healing cream has been developed for veterinary applications.

  20. Chlorhexidine-calcium phosphate nanoparticles - Polymer mixer based wound healing cream and their applications.

    Science.gov (United States)

    Viswanathan, Kaliyaperumal; Monisha, P; Srinivasan, M; Swathi, D; Raman, M; Dhinakar Raj, G

    2016-10-01

    In this work, we developed a wound healing cream composed of two different polymers, namely chitosan and gelatin with chlorhexidine along with calcium phosphate nanoparticles. The physicochemical properties of the prepared cream were investigated based on SEM, EDX, Raman, FTIR and the results indicated that the cream contained gelatin, chitosan, calcium phosphate nanoparticles and chlorhexidine. The maximum swelling ratio studies indicated that the ratio was around of 52±2.2 at pH7.4 and the value was increased in acidic and alkaline pH. The antimicrobial activity was tested against bacteria and the results indicated that, both chlorhexidine and the hybrid cream devoid of chlorhexidine exhibited antimicrobial activity but the chlorhexidine impregnated cream showed three fold higher antimicrobial activity than without chlorhexidine. In vivo wound healing promoting activities of hybrid cream containing 0.4mg/L chlorhexidine were evaluated on surgically induced dermal wounds in mice. The results indicated that the cream with incorporated chlorhexidine significantly enhanced healing compared with the control samples. For the field validations, the veterinary clinical animals were treated with the cream and showed enhanced healing capacity. In conclusion, a simple and efficient method for design of a novel wound healing cream has been developed for veterinary applications. PMID:27287150

  1. Trends in broad-spectrum antibiotic prescribing for children with acute otitis media in the United States, 1998–2004

    Directory of Open Access Journals (Sweden)

    Gambler Angela S

    2009-06-01

    Full Text Available Abstract Background Overuse of broad-spectrum antibiotics is associated with antibiotic resistance. Acute otitis media (AOM is responsible for a large proportion of antibiotics prescribed for US children. Rates of broad-spectrum antibiotic prescribing for AOM are unknown. Methods Analysis of the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey, 1998 to 2004 (N = 6,878. Setting is office-based physicians, hospital outpatient departments, and emergency departments. Patients are children aged 12 years and younger prescribed antibiotics for acute otitis media. Main outcome measure is percentage of broad-spectrum antibiotics, defined as amoxicillin/clavulanate, macrolides, cephalosporins and quinolones. Results Broad-spectrum prescribing for acute otitis media increased from 34% of visits in 1998 to 45% of visits in 2004 (P Conclusion Prescribing of broad-spectrum antibiotics for acute otitis media has steadily increased from 1998 to 2004. Associations with non-clinical factors suggest potential for improvement in prescribing practice.

  2. Survey of pharmacists and physicians on drug interactions between combined oral contraceptives and broad-spectrum antibiotics

    Directory of Open Access Journals (Sweden)

    Masters KP

    2009-09-01

    Full Text Available Objective: To evaluate physician and pharmacist knowledge on potential drug interactions between combined oral contraceptives (COC and broad-spectrum antibiotics and determine if any difference exists between responses.Methods: Two hundred licensed retail pharmacists and 200 licensed family practice physicians in the states of Virginia, West Virginia, and Maryland were mailed an anonymous survey between August 2007 and November 2007. The survey consisted of 3 short questions asking practitioners about their current opinion on drug interactions with COCs and whether an alternative form of contraception is needed for patients taking COC and concomitant broad-spectrum antibiotics. The main outcome measure of the survey included: identifying how physicians and pharmacists handle prescribing or dispensing COCs along with broad-spectrum antibiotics. Gender, educational degree, and years in practice were also collected. Results: A total of 182 participants returned the surveys (57% were physicians and 43% were pharmacists. When asked if broad-spectrum antibiotics have a clinically significant interaction with COCs, 82.7% of physicians and 88.5% of pharmacists answered, “yes”. Of the respondents, 84.6% stated that the drug interaction warrants the patient to be advised to use back-up contraception. A total of 90.1% stated that they currently instruct patients to use back-up contraception when prescribing or dispensing antibiotics to a patient who is on COC, with no statistically significant difference existing between the responses of the pharmacists and the physicians.Conclusion: Physicians and pharmacists believe that broad-spectrum antibiotics decrease the effectiveness of COCs. These practitioners warn their patients of this interaction and advise the use of back-up contraception. More education should be provided to practitioners regarding the data concerning COCs and broad spectrum antibiotics and lack of a proven interaction.

  3. Current evidence on chlorhexidine, toothpaste, gels, and mouthwashes

    NARCIS (Netherlands)

    D.E. Slot; F.A. van der Weijden

    2015-01-01

    The universal advice from dental care professionals is to brush twice daily with a fluoride dentifrice. It would be ideal to incorporate an effective antimicrobial agent such as chlorhexidine (CHX) in a dentifrice formulation. CHX dentifrice can be successfully formulated and will inhibit plaque gro

  4. Changes in Cell Viability of Wounded Fibroblasts following Laser Irradiation in Broad-Spectrum or Infrared Light

    OpenAIRE

    Hawkins, Denise; Abrahamse, Heidi

    2007-01-01

    Objective. This study aimed to establish if broad-spectrum or infrared (IR) light in combination with laser therapy can assist phototherapy to improve the cell function of wounded cells. Background. The effect of laser light may be partly or completely reduced by broad-spectrum light. Methods. Wounded human skin fibroblasts were irradiated with 5 J/cm2 using a helium-neon laser, a diode laser, or an Nd:YAG laser in the dark, in the light, or in IR. Changes in cell viability were evaluated by ...

  5. Broad-spectrum β-lactamases among Enterobacteriaceae of animal origin: molecular aspects, mobility and impact on public health

    OpenAIRE

    Smet, Annemieke; Martel, An; Persoons, Davy; Dewulf, Jeroen; Heyndrickx, Marc; Herman, Lieve; Haesebrouck, Freddy; Butaye, Patrick

    2010-01-01

    Broad-spectrum β-lactamase genes (coding for extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases) have been frequently demonstrated in the microbiota of food-producing animals. This may pose a human health hazard since these genes may be present in zoonotic bacteria, which would cause a direct problem. They can also be present in commensals, which may act as a reservoir of resistance genes for pathogens causing disease both in humans and animals. Broad-spectrum β-lactamase genes ...

  6. Broad-spectrum light versus blue light for phototherapy in neonatal hyperbilirubinemia: a randomized controlled trial.

    Science.gov (United States)

    Pratesi, Simone; Di Fabio, Sandra; Bresci, Cecilia; Di Natale, Cecilia; Bar, Shahar; Dani, Carlo

    2015-07-01

    Phototherapy is standard care for treatment of neonatal hyperbilirubinemia. Our aim was to compare the effectiveness of broad-spectrum light (BSL) to that of blue light emitting diodes (LED) phototherapy for the treatment of jaundiced late preterm and term infants. Infants with gestational age from 35(+0) to 41(+6) weeks of gestation and nonhemolytic hyperbilirubinemia were randomized to treatment with BSL phototherapy or blue LED phototherapy. A total of 20 infants were included in the blue LED phototherapy group and 20 in the BSL phototherapy group. The duration of phototherapy was lower in the BSL than in the blue LED phototherapy group (15.8 ± 4.9 vs. 20.6 ± 6.0 hours; p = 0.009), and infants in the former group had a lower probability (p = 0.015) of remaining in phototherapy than infants in the latter. We concluded that BSL phototherapy is more effective than blue LED phototherapy for the treatment of hyperbilirubinemia in late preterm and term infants. Our data suggest that these results are not due to the different irradiance of the two phototherapy systems, but probably depend on their different peak light emissions. PMID:25545446

  7. Broad spectrum pro-quorum-sensing molecules as inhibitors of virulence in vibrios.

    Directory of Open Access Journals (Sweden)

    Wai-Leung Ng

    Full Text Available Quorum sensing (QS is a bacterial cell-cell communication process that relies on the production and detection of extracellular signal molecules called autoinducers. QS allows bacteria to perform collective activities. Vibrio cholerae, a pathogen that causes an acute disease, uses QS to repress virulence factor production and biofilm formation. Thus, molecules that activate QS in V. cholerae have the potential to control pathogenicity in this globally important bacterium. Using a whole-cell high-throughput screen, we identified eleven molecules that activate V. cholerae QS: eight molecules are receptor agonists and three molecules are antagonists of LuxO, the central NtrC-type response regulator that controls the global V. cholerae QS cascade. The LuxO inhibitors act by an uncompetitive mechanism by binding to the pre-formed LuxO-ATP complex to inhibit ATP hydrolysis. Genetic analyses suggest that the inhibitors bind in close proximity to the Walker B motif. The inhibitors display broad-spectrum capability in activation of QS in Vibrio species that employ LuxO. To the best of our knowledge, these are the first molecules identified that inhibit the ATPase activity of a NtrC-type response regulator. Our discovery supports the idea that exploiting pro-QS molecules is a promising strategy for the development of novel anti-infectives.

  8. A natural and broad spectrum nootropic substance for treatment of SDAT--the Ginkgo biloba extract.

    Science.gov (United States)

    Fünfgeld, E W

    1989-01-01

    The efficacy of the Ginkgo biloba extract was not only found clinically or in standardised ratings but also documented by objective data, obtained by a computerized EEG method, the DYNAMIC BRAIN MAPPING and BRAIN FUNCTION MONITORING SYSTEM (Dr. T. Itil, New York). A one year open trial comprise 25 parkinson patients with additional signs of SDAT. Data from 3 selected cases were given: The short time efficacy of the substance after the infusion and the long-term result after the oral medication. The maps showed less slower and more faster waves. Without any side effects the Ginkgo biloba extract seems to be a substance with a broad spectrum of influence. Our therapeutic findings in parkinsonian patients with SDAT and the data taken from healthy elderly volunteers revealed that the computerized EEG method may have another big advantage: It seems that the so-called anteriorisation of the Theta waves can be taken as a preclinical sign of an incipient change in brain metabolism. As a consequence--it might be that these changes are reversible by an adequate nootropic treatment. Further studies and treatment experiences must confirm these preliminary findings. PMID:2602410

  9. Broad-spectrum identification and discrimination between biothreat agents and near-neighbor species

    Science.gov (United States)

    Malanoski, Anthony P.; Leski, Tomasz A.; Cheng, Luke; Wang, Zheng; Stenger, David A.; Lin, Baochuan

    2009-05-01

    A comprehensive resequencing microarray "Tropical and Emerging Infections (TessArray RPM-TEI 1.0 array)" has been developed to identify and distinguish between biothreat organisms of interest and genetically close related species. This array has undergone validation using an innovative approach where synthetic DNA fragments are used for organisms that it is not safe to work with outside a biosafety 3 facilities. The approach was confirmed from testing a subset of target organisms, such as Ebola viruses and Lassa viruses, at USAMRIID. Most potential biothreat organisms are actually endemic in some part of the world. Proper surveillance of biothreat agents will require some form of monitoring the evolution of the indigenous organisms under their natural environment, so when changes in the organisms occur, the diagnostic assays for these organisms can be reviewed to assure they still provide detection. Using the resequencing microarray (RPM) for detection in locations such as the Africa can support indigenous monitoring as it provides sequence information. An ongoing collaboration with Njala University aims to establish a broad-spectrum pathogen surveillance capability in the Republic of Sierra Leone, West Africa using RPM technology combined with a Geographic Information System. This has the potential to improve the public health efforts in an infected area as well as provide monitoring of the changes occurring to a biothreat organism, i.e. Lassa viruses, in its natural location.

  10. Human DDX3 protein is a valuable target to develop broad spectrum antiviral agents.

    Science.gov (United States)

    Brai, Annalaura; Fazi, Roberta; Tintori, Cristina; Zamperini, Claudio; Bugli, Francesca; Sanguinetti, Maurizio; Stigliano, Egidio; Esté, José; Badia, Roger; Franco, Sandra; Martinez, Miguel A; Martinez, Javier P; Meyerhans, Andreas; Saladini, Francesco; Zazzi, Maurizio; Garbelli, Anna; Maga, Giovanni; Botta, Maurizio

    2016-05-10

    Targeting a host factor essential for the replication of different viruses but not for the cells offers a higher genetic barrier to the development of resistance, may simplify therapy regimens for coinfections, and facilitates management of emerging viral diseases. DEAD-box polypeptide 3 (DDX3) is a human host factor required for the replication of several DNA and RNA viruses, including some of the most challenging human pathogens currently circulating, such as HIV-1, Hepatitis C virus, Dengue virus, and West Nile virus. Herein, we showed for the first time, to our knowledge, that the inhibition of DDX3 by a small molecule could be successfully exploited for the development of a broad spectrum antiviral agent. In addition to the multiple antiviral activities, hit compound 16d retained full activity against drug-resistant HIV-1 strains in the absence of cellular toxicity. Pharmacokinetics and toxicity studies in rats confirmed a good safety profile and bioavailability of 16d. Thus, DDX3 is here validated as a valuable therapeutic target. PMID:27118832

  11. Broad-spectrum resistance to Bacillus thuringiensis toxins by western corn rootworm (Diabrotica virgifera virgifera).

    Science.gov (United States)

    Jakka, Siva R K; Shrestha, Ram B; Gassmann, Aaron J

    2016-06-14

    The evolution of resistance and cross-resistance threaten the sustainability of genetically engineered crops that produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt). Western corn rootworm, Diabrotica virgifera virgifera LeConte, is a serious pest of maize and has been managed with Bt maize since 2003. We conducted laboratory bioassays with maize hybrids producing Bt toxins Cry3Bb1, mCry3A, eCry3.1Ab, and Cry34/35Ab1, which represent all commercialized Bt toxins for management of western corn rootworm. We tested populations from fields where severe injury to Cry3Bb1 maize was observed, and populations that had never been exposed to Bt maize. Consistent with past studies, bioassays indicated that field populations were resistant to Cry3Bb1 maize and mCry3A maize, and that cross-resistance was present between these two types of Bt maize. Additionally, bioassays revealed resistance to eCry3.1Ab maize and cross-resistance among Cry3Bb1, mCry3A and eCry3.1Ab. However, no resistance or cross-resistance was detected for Cry34/35Ab1 maize. This broad-spectrum resistance illustrates the potential for insect pests to develop resistance rapidly to multiple Bt toxins when structural similarities are present among toxins, and raises concerns about the long-term durability of Bt crops for management of some insect pests.

  12. Broad-spectrum sun-protective action of Porphyra-334 derived from Porphyra vietnamensis

    Directory of Open Access Journals (Sweden)

    Saurabh Bhatia

    2010-01-01

    Full Text Available There are enormous UV-protective compounds present in the current world market, out of which 98% give protection against UV-B range and the remaining 2% are potent against far UV-A range only. Furthermore, these synthetic compounds have various problems related to photo-stability and cross-stability. There is a vital need of sunscreen agents that will remain stable for prolonged periods and provide broad-spectrum protection against harmful UV range. The Indian Ocean contains large amounts of macro-algae which synthesize varied amount of mycosporine amino acids, "sun-protective compounds" by shikmic acid pathway. In the present study, we have evaluated the sunscreen protection provided by Porphyra-334, a mycosporine amino acid isolated from Indian sp. of Porphyra. Furthermore, the isolated compound was detected by high performance thin layer chromatography (HPTLC fingerprinting, high performance liquid chromatography (HPLC and ultraviolet (UV, whereas nuclear magnetic resonance (NMR spectroscopy and infrared spectrometry were used for its structural characterization. Stability studies were performed under different storage and pH conditions. Ultimately a sunscreen formulation was developed and its potential against marketed Aloe vera gel was evaluated by in vitro sunscreen protection method. It was observed that sunscreen potential of Porphyra-334 was 5.11-fold greater than that of the marketed Aloe vera gel preparation.

  13. Analysis of mobile health applications for a broad spectrum of consumers: a user experience approach.

    Science.gov (United States)

    García-Gómez, Juan M; de la Torre-Díez, Isabel; Vicente, Javier; Robles, Montserrat; López-Coronado, Miguel; Rodrigues, Joel J

    2014-03-01

    Mobile health (m-health) apps can bring health prevention and promotion to the general population. The main purpose of this article is to analyze different m-health apps for a broad spectrum of consumers by means of three different experiences. This goal was defined following the strategic documents generated by the main prospective observatories of Information and Communications Technology for health. After a general exploration of the app markets, we analyze the entries of three specific themes focused in this article: type 2 diabetes, obesity, and breast-feeding. The user experiences reported in this study mostly cover the segments of (1) chronically monitored consumers through a Web mobile app for predicting type 2 diabetes (Diab_Alert app), (2) information seekers through a mobile app for maternity (Lactation app) and partially (3) the motivated healthy consumers through a mobile app for a dietetic monitoring and assessment (SapoFit app). These apps were developed by the authors of this work. PMID:24550566

  14. Broad spectrum pro-quorum-sensing molecules as inhibitors of virulence in vibrios.

    Science.gov (United States)

    Ng, Wai-Leung; Perez, Lark; Cong, Jianping; Semmelhack, Martin F; Bassler, Bonnie L

    2012-01-01

    Quorum sensing (QS) is a bacterial cell-cell communication process that relies on the production and detection of extracellular signal molecules called autoinducers. QS allows bacteria to perform collective activities. Vibrio cholerae, a pathogen that causes an acute disease, uses QS to repress virulence factor production and biofilm formation. Thus, molecules that activate QS in V. cholerae have the potential to control pathogenicity in this globally important bacterium. Using a whole-cell high-throughput screen, we identified eleven molecules that activate V. cholerae QS: eight molecules are receptor agonists and three molecules are antagonists of LuxO, the central NtrC-type response regulator that controls the global V. cholerae QS cascade. The LuxO inhibitors act by an uncompetitive mechanism by binding to the pre-formed LuxO-ATP complex to inhibit ATP hydrolysis. Genetic analyses suggest that the inhibitors bind in close proximity to the Walker B motif. The inhibitors display broad-spectrum capability in activation of QS in Vibrio species that employ LuxO. To the best of our knowledge, these are the first molecules identified that inhibit the ATPase activity of a NtrC-type response regulator. Our discovery supports the idea that exploiting pro-QS molecules is a promising strategy for the development of novel anti-infectives. PMID:22761573

  15. Novel gramicidin formulations in cationic lipid as broad-spectrum microbicidal agents

    OpenAIRE

    Ragioto DA; Carrasco LD; Carmona-Ribeiro AM

    2014-01-01

    Danielle AMT Ragioto, Letícia DM Carrasco, Ana M Carmona-Ribeiro Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil Abstract: Dioctadecyldimethylammonium bromide (DODAB) is an antimicrobial lipid that can be dispersed as large closed bilayers (LV) or bilayer disks (BF). Gramicidin (Gr) is an antimicrobial peptide assembling as channels in membranes and increasing their permeability towards ca...

  16. Uses of antimicrobial genes from microbial genome

    Science.gov (United States)

    Sorek, Rotem; Rubin, Edward M.

    2013-08-20

    We describe a method for mining microbial genomes to discover antimicrobial genes and proteins having broad spectrum of activity. Also described are antimicrobial genes and their expression products from various microbial genomes that were found using this method. The products of such genes can be used as antimicrobial agents or as tools for molecular biology.

  17. Wild coastline birds as reservoirs of broad-spectrum-β-lactamase-producing Enterobacteriaceae in Miami Beach, Florida.

    Science.gov (United States)

    Poirel, Laurent; Potron, Anaïs; De La Cuesta, Carolina; Cleary, Timothy; Nordmann, Patrice; Munoz-Price, L Silvia

    2012-05-01

    A high rate of broad-spectrum-β-lactamase-producing Escherichia coli isolates was identified from seagull and pelican feces collected in the Miami Beach, Florida, area. The most commonly identified resistance determinants were CMY-2 and CTX-M-15. Those wild birds might be therefore considered vehicles for wide dissemination of multidrug-resistant Enterobacteriaceae in the United States.

  18. Successful five-item triage for the broad spectrum of mental disorders in pregnancy - A validation study

    NARCIS (Netherlands)

    C. Quispel (Chantal); T.A.J. Schneider (Tom); W.J.G. Hoogendijk (Witte); G.J. Bonsel (Gouke); M.P. Lambregtse-van den Berg (Mijke)

    2015-01-01

    textabstractBackground: Mental disorders are prevalent during pregnancy, affecting 10% of women worldwide. To improve triage of a broad spectrum of mental disorders, we investigated the decision impact validity of: 1) a short set of currently used psychiatric triage items, 2) this set with the inclu

  19. Competitive Interaction Between Phytophthora Infestans Effectors Leads to Increased Aggressiveness on Plants Containing Broad-spectrum Late Blight Resistance

    Science.gov (United States)

    The resistance (R) gene RB confers broad-spectrum resistance to potato late blight and belongs. The RB protein recognizes the presence of members of the Phytophthora infestans effector family IPI-O to elicit resistance. Most isolates of the pathogen contain IPI-O variants that are recognized by R...

  20. Wild Coastline Birds as Reservoirs of Broad-Spectrum-β-Lactamase-Producing Enterobacteriaceae in Miami Beach, Florida

    OpenAIRE

    Poirel, L.; Potron, A.; de la Cuesta, C.; Cleary, T.; Nordmann, P; Munoz-Price, L. S.

    2012-01-01

    A high rate of broad-spectrum-β-lactamase-producing Escherichia coli isolates was identified from seagull and pelican feces collected in the Miami Beach, Florida, area. The most commonly identified resistance determinants were CMY-2 and CTX-M-15. Those wild birds might be therefore considered vehicles for wide dissemination of multidrug-resistant Enterobacteriaceae in the United States.

  1. The broad-spectrum cation channel blocker pinokalant (LOE 908 MS) reduces brain infarct volume in rats

    DEFF Research Database (Denmark)

    Christensen, Thomas; Wienrich, Marion; Ensinger, Helmut A;

    2005-01-01

    Activation of cation channels conducting Ca2+, Na+ and K+ is involved in the pathogenesis of infarction in experimental focal cerebral ischaemia. Pinokalant (LOE 908 MS) is a novel broad-spectrum inhibitor of several subtypes of such channels and has previously been shown to improve the metabolic...

  2. Novel gramicidin formulations in cationic lipid as broad-spectrum microbicidal agents

    Directory of Open Access Journals (Sweden)

    Ragioto DA

    2014-06-01

    Full Text Available Danielle AMT Ragioto, Letícia DM Carrasco, Ana M Carmona-Ribeiro Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil Abstract: Dioctadecyldimethylammonium bromide (DODAB is an antimicrobial lipid that can be dispersed as large closed bilayers (LV or bilayer disks (BF. Gramicidin (Gr is an antimicrobial peptide assembling as channels in membranes and increasing their permeability towards cations. In mammalian cells, DODAB and Gr have the drawbacks of Gram-positive resistance and high toxicity, respectively. In this study, DODAB bilayers incorporating Gr showed good antimicrobial activity and low toxicity. Techniques employed were spectroscopy, photon correlation spectroscopy for sizing and evaluation of the surface potential at the shear plane, turbidimetric detection of dissipation of osmotic gradients in LV/Gr, determination of bacterial cell lysis, and counting of colony-forming units. There was quantitative incorporation of Gr and development of functional channels in LV. Gr increased the bilayer charge density in LV but did not affect the BF charge density, with localization of Gr at the BF borders. DODAB/Gr formulations substantially reduce Gr toxicity against eukaryotic cells and advantageously broaden the antimicrobial activity spectrum, effectively killing Escherichia coli and Staphylococcus aureus bacteria with occurrence of cell lysis. Keywords: antimicrobial peptides, cationic bilayers, bilayer fragments, dioctadecyldimethylammonium bromide, gramicidin A, self-assembly

  3. Manganese Oxide Nanoarchitectures as Broad-Spectrum Sorbents for Toxic Gases.

    Science.gov (United States)

    Long, Jeffrey W; Wallace, Jean M; Peterson, Gregory W; Huynh, Kim

    2016-01-20

    We demonstrate that sol-gel-derived manganese oxide (MnOx) nanoarchitectures exhibit broad-spectrum filtration activity for three chemically diverse toxic gases: NH3, SO2, and H2S. Manganese oxides are synthesized via the reaction of NaMnO4 and fumaric acid to form monolithic gels of disordered, mixed-valent Na-MnOx; incorporated Na(+) is readily exchanged for H(+) by subsequent acid rinsing to form a more crystalline H-MnOx phase. For both Na-MnOx and H-MnOx forms, controlled pore-fluid removal yields either densified, yet still mesoporous, xerogels or low-density aerogels (prepared by drying from supercritical CO2). The performance of these MnOx nanoarchitectures as filtration media is assessed using dynamic-challenge microbreakthrough protocols. We observe technologically relevant sorption capacities under both dry conditions and wet (80% relative humidity) for each of the three toxic industrial chemicals investigated. The Na-MnOx xerogels and aerogels provide optimal performance with the aerogel exhibiting maximum sorption capacities of 39, 200, and 680 mg g(-1) for NH3, SO2, and H2S, respectively. Postbreakthrough characterization using X-ray photoelectron spectroscopy (XPS) and diffuse-reflectance infrared Fourier transform spectroscopy (DRIFTS) confirms that NH3 is captured and partially protonated within the MnOx structure, while SO2 undergoes oxidation by the redox-active oxide to form adsorbed sulfate at the MnOx surface. Hydrogen sulfide is also oxidized to form a combination of sulfate and sulfur/polysulfide products, concomitant with a decrease in the average Mn oxidation state from 3.43 to 2.94 and generation of a MnOOH phase. PMID:26741498

  4. Extensive sequence variation in rice blast resistance gene Pi54 makes it broad spectrum in nature

    Directory of Open Access Journals (Sweden)

    Shallu eThakur

    2015-05-01

    Full Text Available Rice blast resistant gene, Pi54 cloned from rice line, Tetep, is effective against diverse isolates of Magnaporthe oryzae. In this study, we prospected the allelic variants of the dominant blast resistance gene from a set of 92 rice lines to determine the nucleotide diversity, pattern of its molecular evolution, phylogenetic relationships and evolutionary dynamics, and to develop allele specific markers. High quality sequences were generated for homologs of Pi54 gene. Using comparative sequence analysis, InDels of variable sizes in all the alleles were observed. Profiling of the selected sites of SNP (Single Nucleotide Polymorphism and amino acids (N sites ≥ 10 exhibited constant frequency distribution of mutational and substitutional sites between the resistance and susceptible rice lines, respectively. A total of 50 new haplotypes based on the nucleotide polymorphism was also identified. A unique haplotype (H_3 was found to be linked to all the resistant alleles isolated from indica rice lines. Unique leucine zipper and tyrosine sulfation sites were identified in the predicted Pi54 proteins. Selection signals were observed in entire coding sequence of resistance alleles, as compared to LRR domains for susceptible alleles. This is a maiden report of extensive variability of Pi54 alleles in different landraces and cultivated varieties, possibly, attributing broad-spectrum resistance to Magnaporthe oryzae. The sequence variation in two consensus region: 163 bp and 144 bp were used for the development of allele specific DNA markers. Validated markers can be used for the selection and identification of better allele(s and their introgression in commercial rice cultivars employing marker assisted selection.

  5. Systems analysis of a RIG-I agonist inducing broad spectrum inhibition of virus infectivity.

    Directory of Open Access Journals (Sweden)

    Marie-Line Goulet

    Full Text Available The RIG-I like receptor pathway is stimulated during RNA virus infection by interaction between cytosolic RIG-I and viral RNA structures that contain short hairpin dsRNA and 5' triphosphate (5'ppp terminal structure. In the present study, an RNA agonist of RIG-I was synthesized in vitro and shown to stimulate RIG-I-dependent antiviral responses at concentrations in the picomolar range. In human lung epithelial A549 cells, 5'pppRNA specifically stimulated multiple parameters of the innate antiviral response, including IRF3, IRF7 and STAT1 activation, and induction of inflammatory and interferon stimulated genes - hallmarks of a fully functional antiviral response. Evaluation of the magnitude and duration of gene expression by transcriptional profiling identified a robust, sustained and diversified antiviral and inflammatory response characterized by enhanced pathogen recognition and interferon (IFN signaling. Bioinformatics analysis further identified a transcriptional signature uniquely induced by 5'pppRNA, and not by IFNα-2b, that included a constellation of IRF7 and NF-kB target genes capable of mobilizing multiple arms of the innate and adaptive immune response. Treatment of primary PBMCs or lung epithelial A549 cells with 5'pppRNA provided significant protection against a spectrum of RNA and DNA viruses. In C57Bl/6 mice, intravenous administration of 5'pppRNA protected animals from a lethal challenge with H1N1 Influenza, reduced virus titers in mouse lungs and protected animals from virus-induced pneumonia. Strikingly, the RIG-I-specific transcriptional response afforded partial protection from influenza challenge, even in the absence of type I interferon signaling. This systems approach provides transcriptional, biochemical, and in vivo analysis of the antiviral efficacy of 5'pppRNA and highlights the therapeutic potential associated with the use of RIG-I agonists as broad spectrum antiviral agents.

  6. Pyrodiversity and the anthropocene: the role of fire in the broad spectrum revolution.

    Science.gov (United States)

    Bird, Douglas W; Bliege Bird, Rebecca; Codding, Brian F

    2016-05-01

    The Anthropocene colloquially refers to a global regime of human-caused environmental modification of earth systems associated with profound changes in patterns of human mobility, as well as settlement and resource use compared with prior eras. Some have argued that the processes generating the Anthropocene are mainly associated with population growth and technological innovation, and thus began only in the late Holocene under conditions of dense sedentism and industrial agriculture.(1) However, it now seems clear that the roots of the Anthropocene lie in complex processes of intensification that significantly predate transitions to agriculture.(2,3) What intensification is remains less clear. For some it is increasing economic productivity that increases carrying capacity, the drivers of which may be too diverse and too local to generalize.(4,5) For others using Boserup's ideas about agrarian intensification, increasing density in hunter-gatherer populations can produce declines in subsistence efficiency that increase incentives for investing labor to boost yield per unit area, which then elevates Malthusian limits on carrying capacity.(6-8) As Morgan(9) demonstrates in a comprehensive review, the legacy of such Boserupian intensification is alive, well, and controversial in hunter-gatherer archeology. This is a result of its potential for illuminating processes involved in transformations of forager socio-political and economic systems, including those dominated by harvesting more immediate-return resources and high residential mobility as well as those characterized by more delayed-return material economies with reduced residential mobility, a broader spectrum of resources, degrees of storage, and greater social stratification. Here we detail hypotheses about the processes involved in such transitions and explore the way that anthropogenic disturbance of ecosystems, especially the use of landscape fire, could be fundamentally entangled with many broad-spectrum

  7. Pyrodiversity and the anthropocene: the role of fire in the broad spectrum revolution.

    Science.gov (United States)

    Bird, Douglas W; Bliege Bird, Rebecca; Codding, Brian F

    2016-05-01

    The Anthropocene colloquially refers to a global regime of human-caused environmental modification of earth systems associated with profound changes in patterns of human mobility, as well as settlement and resource use compared with prior eras. Some have argued that the processes generating the Anthropocene are mainly associated with population growth and technological innovation, and thus began only in the late Holocene under conditions of dense sedentism and industrial agriculture.(1) However, it now seems clear that the roots of the Anthropocene lie in complex processes of intensification that significantly predate transitions to agriculture.(2,3) What intensification is remains less clear. For some it is increasing economic productivity that increases carrying capacity, the drivers of which may be too diverse and too local to generalize.(4,5) For others using Boserup's ideas about agrarian intensification, increasing density in hunter-gatherer populations can produce declines in subsistence efficiency that increase incentives for investing labor to boost yield per unit area, which then elevates Malthusian limits on carrying capacity.(6-8) As Morgan(9) demonstrates in a comprehensive review, the legacy of such Boserupian intensification is alive, well, and controversial in hunter-gatherer archeology. This is a result of its potential for illuminating processes involved in transformations of forager socio-political and economic systems, including those dominated by harvesting more immediate-return resources and high residential mobility as well as those characterized by more delayed-return material economies with reduced residential mobility, a broader spectrum of resources, degrees of storage, and greater social stratification. Here we detail hypotheses about the processes involved in such transitions and explore the way that anthropogenic disturbance of ecosystems, especially the use of landscape fire, could be fundamentally entangled with many broad-spectrum

  8. Broad-spectrum resistance to Bacillus thuringiensis toxins by western corn rootworm (Diabrotica virgifera virgifera).

    Science.gov (United States)

    Jakka, Siva R K; Shrestha, Ram B; Gassmann, Aaron J

    2016-01-01

    The evolution of resistance and cross-resistance threaten the sustainability of genetically engineered crops that produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt). Western corn rootworm, Diabrotica virgifera virgifera LeConte, is a serious pest of maize and has been managed with Bt maize since 2003. We conducted laboratory bioassays with maize hybrids producing Bt toxins Cry3Bb1, mCry3A, eCry3.1Ab, and Cry34/35Ab1, which represent all commercialized Bt toxins for management of western corn rootworm. We tested populations from fields where severe injury to Cry3Bb1 maize was observed, and populations that had never been exposed to Bt maize. Consistent with past studies, bioassays indicated that field populations were resistant to Cry3Bb1 maize and mCry3A maize, and that cross-resistance was present between these two types of Bt maize. Additionally, bioassays revealed resistance to eCry3.1Ab maize and cross-resistance among Cry3Bb1, mCry3A and eCry3.1Ab. However, no resistance or cross-resistance was detected for Cry34/35Ab1 maize. This broad-spectrum resistance illustrates the potential for insect pests to develop resistance rapidly to multiple Bt toxins when structural similarities are present among toxins, and raises concerns about the long-term durability of Bt crops for management of some insect pests. PMID:27297953

  9. Anti-microbial efficacy of green tea and chlorhexidine mouth rinses against Streptococcus mutans, Lactobacilli spp. and Candida albicans in children with severe early childhood caries: A randomized clinical study

    Directory of Open Access Journals (Sweden)

    Ann Thomas

    2016-01-01

    Full Text Available Introduction: Green tea is a beverage which is consumed worldwide and is reported to have anti-cariogenic effect. So, if it was as effective as chlorhexidine (CHX mouth rinse against cariogenic microbes it could be considered a natural, economical alternative. The purpose of this study was to evaluate and compare the anti-microbial efficacy of 0.5% green tea and 0.2% CHX mouth rinses against Streptococcus Mutans, Lactobacilli spp. and Candida Albicans. Materials and Methods: 30 children aged 4-6 years with S-ECC (based ondefs score were selected. Children were divided randomly into 2 equal groups and were asked to rinse with the prescribed mouth rinse once daily for 2 weeks after breakfast under supervision. A base-line and post rinsing non-stimulated whole salivary sample (2 ml was collected and tested for the number of colony forming units. The data was statistically analyzed using SPSS v16.0 software with one-way ANOVA and Tukey′sPOSTHOC test. Results: A statistically significant fall in colony count was found with both the mouth rinses in Streptococcus Mutans (P < 0.001, P < 0.001 and lactobacilli (P < 0.001, P < 0.001 but not against Candida albicans (P = 0.264, P = 0.264. Against Streptococcus Mutans, green tea mouth rinse was found to be significantly better than CHX mouth rinse (P = 0.005. Against lactobacilli spp, CHX mouth rinse was significantly better than green tea mouth rinse (P < 0.001. Conclusion: Green tea mouth rinse can be considered safe, economical and used without much concern. However, further studies are recommended.

  10. A mechanistic paradigm for broad-spectrum antivirals that target virus-cell fusion.

    Directory of Open Access Journals (Sweden)

    Frederic Vigant

    .01 delayed the time to death in a murine lethal challenge model of Rift Valley Fever Virus (RVFV. The viral membrane may be a viable target for broad-spectrum antivirals that target virus-cell fusion.

  11. Pharmacy sales data versus ward stock accounting for the surveillance of broad-spectrum antibiotic use in hospitals

    Directory of Open Access Journals (Sweden)

    Haug Jon B

    2011-12-01

    Full Text Available Abstract Background Antibiotic consumption in hospitals is commonly measured using the accumulated amount of drugs delivered from the pharmacy to ward held stocks. The reliability of this method, particularly the impact of the length of the registration periods, has not been evaluated and such evaluation was aim of the study. Methods During 26 weeks, we performed a weekly ward stock count of use of broad-spectrum antibiotics - that is second- and third-generation cephalosporins, carbapenems, and quinolones - in five hospital wards and compared the data with corresponding pharmacy sales figures during the same period. Defined daily doses (DDDs for antibiotics were used as measurement units (WHO ATC/DDD classification. Consumption figures obtained with the two methods for different registration intervals were compared by use of intraclass correlation analysis and Bland-Altman statistics. Results Broad-spectrum antibiotics accounted for a quarter to one-fifth of all systemic antibiotics (ATC group J01 used in the hospital and varied between wards, from 12.8 DDDs per 100 bed days in a urological ward to 24.5 DDDs in a pulmonary diseases ward. For the entire study period of 26 weeks, the pharmacy and ward defined daily doses figures for all broad-spectrum antibiotics differed only by 0.2%; however, for single wards deviations varied from -4.3% to 6.9%. The intraclass correlation coefficient, pharmacy versus ward data, increased from 0.78 to 0.94 for parenteral broad-spectrum antibiotics with increasing registration periods (1-4 weeks, whereas the corresponding figures for oral broad-spectrum antibiotics (ciprofloxacin were from 0.46 to 0.74. For all broad-spectrum antibiotics and for parenteral antibiotics, limits of agreement between the two methods showed, according to Bland-Altman statistics, a deviation of ± 5% or less from average mean DDDs at 3- and 4-weeks registration intervals. Corresponding deviation for oral antibiotics was ± 21% at a 4

  12. Molecular epidemiology and antimicrobial susceptibility of extended- and broad-spectrum beta-lactamase-producing Klebsiella pneumoniae isolated in Portugal.

    Science.gov (United States)

    Mendonça, Nuno; Ferreira, Eugénia; Louro, Deolinda; Caniça, Manuela

    2009-07-01

    All 187 Klebsiella pneumoniae isolated over six consecutive months of 1999 in 17 Portuguese health institutions were studied: 89% were resistant to ampicillin, 31% to trimethoprim/sulfamethoxazole, 17% to aminoglycosides and 3% to fluoroquinolones; 16% were multidrug-resistant and 14% expressed an extended-spectrum beta-lactamase (ESBL) phenotype confirmed by genotyping. Molecular methods identified: 11 isolates possessing bla(ESBL-SHV) genes (bla(SHV-2A), bla(SHV-5), bla(SHV-12) and bla(SHV-55)), 9 isolates with bla(ESBL-TEM) (bla(TEM-3), bla(TEM-10) and bla(TEM-24)) and 7 isolates with bla(GES-1), encoding ESBL enzymes; and 160 isolates with bla(SHV-1) and bla(SHV-type) encoding non-ESBL enzymes. Overall, 15 new beta-lactamases were detected: SHV-60 to SHV-62, SHV-71 and SHV-73 to SHV-83. The genetic relatedness of 108 isolates was studied by pulsed-field gel electrophoresis (PFGE) analysis. The isolates were diverse and 18 clusters were defined, the largest including 12 isolates of different specimens, 6 of which expressed GES-1 enzymes. Twenty additional strains isolated during a second period (March-November 2006) in three of the participating hospitals contained ESBL-encoding genes, whereas none of the isolates in the same hospitals in 1999 carried such genes: bla(SHV-5), bla(SHV-12), bla(TEM-10), bla(TEM-52), bla(CTX-M-15), bla(CTX-M-32) and bla(CTX-M-61) (first described in the country). In this period, three new enzymes were detected: SHV-106 to SHV-108. We provide evidence that the genotypes of K. pneumoniae isolates is changing towards the emergence of ESBL enzymes. PMID:19272757

  13. A crustin isoform from black tiger shrimp, Penaeus monodon exhibits broad spectrum anti-bacterial activity

    Directory of Open Access Journals (Sweden)

    Debashis Banerjee

    2015-11-01

    Full Text Available Crustaceans have a powerful non-specific immune mechanism that responds to pathogen invasion and together with cellular responses, generates powerful humoral factors such as antimicrobial peptides. Crustins are a diverse class of antimicrobial peptides that are expressed by the circulating haemocytes of crustaceans. Several isoforms of this molecule are reported and in this study, one isoform from the black tiger shrimp, Penaeus monodon was cloned and expressed in Escherichia coli SG 13009. The purified recombinant crustin peptide had a molecular weight of 22 kDa and exhibited potent anti-bacterial activity in vitro against several Gram positive and Gram negative bacteria that included pathogens of aquatic animals and humans. The recombinant crustin showed a minimal inhibitory concentration of 0.5 μg ml−1 against the vibrio pathogens of shrimp, which suggests its promise for application in aquaculture.

  14. Discovery of New Imidazole Derivatives Containing the 2,4-Dienone Motif with Broad-Spectrum Antifungal and Antibacterial Activity

    OpenAIRE

    Chunli Liu; Ce Shi; Fei Mao; Yong Xu; Jinyan Liu; Bing Wei; Jin Zhu; Mingjie Xiang; Jian Li

    2014-01-01

    A compound containing an imidazole moiety and a 2,4-dienone motif with significant activity toward several fungi was discovered in a screen for new antifungal compounds. Then, a total of 26 derivatives of this compound were designed, synthesized and evaluated through in vitro and in vivo antifungal activity assays. Several compounds exhibited improved antifungal activities compared to the lead compound. Of the derivatives, compounds 31 and 42 exhibited strong, broad-spectrum inhibitory effect...

  15. NBS Proifling Identiifes Potential Novel Locus from Solanum demissum That Confers Broad-Spectrum Resistance to Phytophthora infestans

    Institute of Scientific and Technical Information of China (English)

    ZHANG Kun; XU Jian-fei; DUAN Shao-guang; PANG Wan-fu; BIAN Chun-song; LIU Jie; JIN Li-ping

    2014-01-01

    Potato late blight, caused by the oomycete pathogen Phytophthora infestans, is the most serious disease of potato worldwide. The adoption of varieties with resistance genes, especially broad-spectrum resistance genes, is the most efifcient approach to control late blight. Solanum demissum is a well-known wild potato species from which 11 race-speciifc resistance genes have been identiifed, however, no broad-spectrum resistance genes like RB have been reported in this species. Here, we report a novel reisistance locus from S. demissum that potentially confer broad-spectrum resistance to late blight. A small segregating population of S. demissum were assessed for resistance to aggressive P. infestans isolates (race 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11). This coupled with nucleotide binding site (NBS) proifling analyses, led to the identiifcation of three fragments that linked to the potential candidate resistance gene(s). Cloning and sequence analysis of these fragments suggested that the identiifed resistance gene locus is located in the region containing R2 resistance gene at chromosome 4. Based on the sequences of the cloned fragments, a co-segregating sequence characterized ampliifed region (SCAR) marker, RDSP, was developed. The newly identiifed marker RDSP will be useful for marker assisted breeding and further cloning of this potential resistance gene locus.

  16. Overexpression of BSR1 confers broad-spectrum resistance against two bacterial diseases and two major fungal diseases in rice.

    Science.gov (United States)

    Maeda, Satoru; Hayashi, Nagao; Sasaya, Takahide; Mori, Masaki

    2016-06-01

    Broad-spectrum disease resistance against two or more types of pathogen species is desirable for crop improvement. In rice, Xanthomonas oryzae pv. oryzae (Xoo), the causal bacteria of rice leaf blight, and Magnaporthe oryzae, the fungal pathogen causing rice blast, are two of the most devastating pathogens. We identified the rice BROAD-SPECTRUM RESISTANCE 1 (BSR1) gene for a BIK1-like receptor-like cytoplasmic kinase using the FOX hunting system, and demonstrated that BSR1-overexpressing (OX) rice showed strong resistance to the bacterial pathogen, Xoo and the fungal pathogen, M. oryzae. Here, we report that BSR1-OX rice showed extended resistance against two other different races of Xoo, and to at least one other race of M. oryzae. In addition, the rice showed resistance to another bacterial species, Burkholderia glumae, which causes bacterial seedling rot and bacterial grain rot, and to Cochliobolus miyabeanus, another fungal species causing brown spot. Furthermore, BSR1-OX rice showed slight resistance to rice stripe disease, a major viral disease caused by rice stripe virus. Thus, we demonstrated that BSR1-OX rice shows remarkable broad-spectrum resistance to at least two major bacterial species and two major fungal species, and slight resistance to one viral pathogen. PMID:27436950

  17. Antibacterial performance of Chlorhexidine acetate treated plain cotton and β-cyclodextrin treated cotton

    OpenAIRE

    Bhaskara, U.R.; Nabers, M.G.D.; Agrawal, P.B.; Warmoeskerken, M.M.C.G.

    2014-01-01

    Cotton was treated with β-cyclodextrin via a crosslinker 1, 2, 3, 4, butane tetracarboxylic acid. β-cyclodextrin attached cotton and plain cotton was treated with the antimicrobial agent Chlorhexidine acetate. The difference in amount of Chlorhexidine acetate loaded onto the two types of fabrics for same application concentrations was noted. These two types of fabrics were then tested for antibacterial performance. The antibacterial activity was tested according to the JIS L 1902 standard usi...

  18. Chlorhexidine Salt-Loaded Polyurethane Orthodontic Chains: In Vitro Release and Antibacterial Activity Studies

    OpenAIRE

    Padois, Karine; Bertholle, Valérie; Pirot, Fabrice; Hyunh, Truc Thanh Ngoc; De Rossi, Alessandra; Colombo, Paolo; Falson, Françoise; Sonvico, Fabio

    2012-01-01

    The widespread use of indwelling medical devices has enormously increased the interest in materials incorporating antibiotics and antimicrobial agents as a means to prevent dangerous device-related infections. Recently, chlorhexidine-loaded polyurethane has been proposed as a material suitable for the production of devices which are able to resist microbial contamination. The aim of the present study was to characterize the in vitro release of chlorhexidine from new polymeric orthodontic chai...

  19. Nuclear Magnetic Resonance Solution Structures of Lacticin Q and Aureocin A53 Reveal a Structural Motif Conserved among Leaderless Bacteriocins with Broad-Spectrum Activity.

    Science.gov (United States)

    Acedo, Jeella Z; van Belkum, Marco J; Lohans, Christopher T; Towle, Kaitlyn M; Miskolzie, Mark; Vederas, John C

    2016-02-01

    Lacticin Q (LnqQ) and aureocin A53 (AucA) are leaderless bacteriocins from Lactococcus lactis QU5 and Staphylococcus aureus A53, respectively. These bacteriocins are characterized by the absence of an N-terminal leader sequence and are active against a broad range of Gram-positive bacteria. LnqQ and AucA consist of 53 and 51 amino acids, respectively, and have 47% identical sequences. In this study, their three-dimensional structures were elucidated using solution nuclear magnetic resonance and were shown to consist of four α-helices that assume a very similar compact, globular overall fold (root-mean-square deviation of 1.7 Å) with a highly cationic surface and a hydrophobic core. The structures of LnqQ and AucA resemble the shorter two-component leaderless bacteriocins, enterocins 7A and 7B, despite having low levels of sequence identity. Homology modeling revealed that the observed structural motif may be shared among leaderless bacteriocins with broad-spectrum activity against Gram-positive organisms. The elucidated structures of LnqQ and AucA also exhibit some resemblance to circular bacteriocins. Despite their similar overall fold, inhibition studies showed that LnqQ and AucA have different antimicrobial potency against the Gram-positive strains tested, suggesting that sequence disparities play a crucial role in their mechanisms of action.

  20. Avaliação da atividade antimicrobiana de adesivo ortodôntico associado a verniz de clorexidina e timol na colagem de braquetes Evaluation of antimicrobial activity of orthodontic adhesive associated with chlorhexidine-thymol varnish in bracket bonding

    Directory of Open Access Journals (Sweden)

    Carolina Freire de Carvalho Calabrich

    2010-08-01

    Full Text Available OBJETIVO: avaliar a atividade antimicrobiana da associação de um adesivo ortodôntico com um verniz de clorexidina e timol. MÉTODOS: foram utilizados 32 pré-molares humanos divididos em 4 grupos. O grupo 1 consistiu do grupo controle, no qual o adesivo utilizado para a colagem do braquete não estava associado a nenhum agente antimicrobiano. Os grupos 2, 3 e 4 foram colados com um sistema adesivo associado a um verniz de clorexidina e timol. Os grupos 3 e 4 foram armazenados em água por 7 dias e 30 dias, respectivamente, enquanto os corpos de prova do grupo 2 foram, logo depois da colagem, colocados em ágar semeado com Streptococcus mutans por 48h a 37ºC. RESULTADOS: os grupos experimentais, com exceção do grupo controle, apresentaram atividade antimicrobiana com tendência de redução do seu potencial de ação com maior tempo de imersão em água. CONCLUSÃO: a associação do verniz de clorexidina a um sistema adesivo utilizado em Ortodontia apresenta-se vantajosa pela sua atividade antimicrobiana.OBJECTIVE: To assess the antimicrobial activity resulting from the association of an orthodontic adhesive with chlorhexidine-thymol varnish. METHODS: Thirty-two extracted human premolars were used, divided into four groups. In Group 1, the control group, the adhesive used to bond the bracket was not associated with any antimicrobial agent. Groups 2, 3 and 4 were bonded with an adhesive system associated with chlorhexidine-thymol varnish. Groups 3 and 4 were stored in water for 7 days and 30 days, respectively, while the specimens from group 2 were, soon after bonding, placed on agar seeded with Streptococcus mutans for 48 hours, at 37º C. RESULTS: The experimental groups, with the exception of the control group, showed antimicrobial activity whose action tended to decline commensurately with the amount of time that they remained immersed in water. CONCLUSIONS: The association of chlorhexidine-thymol varnish with an adhesive system used in

  1. Broad-spectrum antibacterial properties of metal-ion doped borate bioactive glasses for clinical applications

    Science.gov (United States)

    Ottomeyer, Megan

    Bioactive glasses with antimicrobial properties can be implemented as coatings on medical devices and implants, as well as a treatment for tissue repair and prevention of common hospital-acquired infections such as MRSA. A borate-containing glass, B3, is also undergoing clinical trials to assess wound-healing properties. The sensitivities of various bacteria to B3, B3-Ag, B3-Ga, and B3-I bioactive glasses were tested. In addition, the mechanism of action for the glasses was studied by spectroscopic enzyme kinetics experiments, Live-Dead staining fluorescence microscopy, and luminescence assays using two gene fusion strains of Escherichia coli. It was found that gram-positive bacteria were more sensitive to all four glasses than gram negative bacteria, and that a single mechanism of action for the glasses is unlikely, as the rates of catalysis for metabolic enzymes as well as membrane permeability were altered after glass exposure.

  2. Imipenem-cilastatin sodium, a broad-spectrum carbapenem antibiotic combination.

    Science.gov (United States)

    Pastel, D A

    1986-09-01

    The chemistry, antimicrobial spectrum, mechanism of action, pharmacology and pharmacokinetics, clinical use, adverse effects, dosage and administration, place in therapy, cost-effectiveness, and formulary considerations of imipenem-cilastatin sodium are reviewed. Imipenem is the first carbapenem antibiotic of the thienamycin class to be used clinically. Imipenem has the widest spectrum of antimicrobial activity of currently available beta-lactam agents and, in contrast to other beta-lactam antibiotics, lacks cross resistance with recently introduced extended-spectrum penicillins and third-generation cephalosporins. Against gram-positive and gram-negative aerobic and anaerobic organisms, imipenem demonstrates excellent activity. Pseudomonas maltophilia, some strains of Pseudomonas cepacia, and Streptococcus faecium are resistant. Strains of methicillin-resistant staphylococci should also be considered resistant to imipenem. For clinical use imipenem is coadministered in equal parts with cilastatin. Cilastatin is a renal dehydropeptidase inhibitor that inhibits the metabolism of imipenem by renal brush-border enzymes, thus increasing imipenem concentrations in urine. Imipenem-cilastatin is administered by the intravenous route only. The adverse reaction profile of imipenem-cilastatin is similar to t that of other beta-lactam antibiotics. Recommended dosage reductions appropriate for renal impairment should be guided by periodic assessments of renal function, with close adherence to recommended dosage schedules, particularly among patients who are predisposed to seizures or receiving anticonvulsant medication. Imipenem-cilastatin performed well in both comparative and noncomparative trials of clinical efficacy and safety. For infections with multiple organisms (e.g., pelvic, intra-abdominal, or soft-tissue infections), imipenem-cilastatin may be a cost-effective and less toxic single-agent alternative to "standard" combination (e.g., aminoglycoside-penicillin plus an

  3. Functionalization of electrospun {beta}-cyclodextrin/polyacrylonitrile (PAN) with silver nanoparticles: Broad-spectrum antibacterial property

    Energy Technology Data Exchange (ETDEWEB)

    Wang Shan [Chemical Engineering College, Inner Mongolia University of Technology, Hohhot, 010051 (China); Bai Jie, E-mail: baijie@imut.edu.cn [Chemical Engineering College, Inner Mongolia University of Technology, Hohhot, 010051 (China); Li Chunping; Zhang Jianbin [Chemical Engineering College, Inner Mongolia University of Technology, Hohhot, 010051 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Novel PAN nanofibers contained {beta}-cyclodextrin and Ag nanoparticles. Black-Right-Pointing-Pointer The composite nanofibers as antibacterial material. Black-Right-Pointing-Pointer The composite nanofibers showed stronger antibacterial activity. - Abstract: Polyacrylonitrile (PAN) nanofibers containing {beta}-cyclodextrin ({beta}-CD) and Ag nanoparticles have been prepared by electrospinning technology. The silver nanoparticles were obtained from the AgNO{sub 3}/PAN/DMF solution, in which AgNO{sub 3} acted as the precursor, DMF as reducing reagent, and PAN as protective agent. Then, {beta}-CD was added to above solution and the resultant Ag/{beta}-CD-PAN/DMF solution was directly electrospun to prepare Ag/{beta}-CD-PAN nanofibers. The morphology of the nanofibers has been characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The antimicrobial properties were investigated by Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) bacteria, and the results indicated that the composite nanofibers showed stronger antibacterial activity.

  4. Rational design of berberine-based FtsZ inhibitors with broad-spectrum antibacterial activity.

    Directory of Open Access Journals (Sweden)

    Ning Sun

    Full Text Available Inhibition of the functional activity of Filamenting temperature-sensitive mutant Z (FtsZ protein, an essential and highly conserved bacterial cytokinesis protein, is a promising approach for the development of a new class of antibacterial agents. Berberine, a benzylisoquinoline alkaloid widely used in traditional Chinese and native American medicines for its antimicrobial properties, has been recently reported to inhibit FtsZ. Using a combination of in silico structure-based design and in vitro biological assays, 9-phenoxyalkyl berberine derivatives were identified as potent FtsZ inhibitors. Compared to the parent compound berberine, the derivatives showed a significant enhancement of antibacterial activity against clinically relevant bacteria, and an improved potency against the GTPase activity and polymerization of FtsZ. The most potent compound 2 strongly inhibited the proliferation of Gram-positive bacteria, including methicillin-resistant S. aureus and vancomycin-resistant E. faecium, with MIC values between 2 and 4 µg/mL, and was active against the Gram-negative E. coli and K. pneumoniae, with MIC values of 32 and 64 µg/mL respectively. The compound perturbed the formation of cytokinetic Z-ring in E. coli. Also, the compound interfered with in vitro polymerization of S. aureus FtsZ. Taken together, the chemical modification of berberine with 9-phenoxyalkyl substituent groups greatly improved the antibacterial activity via targeting FtsZ.

  5. Delay in the administration of appropriate antimicrobial therapy in Staphylococcus aureus bloodstream infection : A prospective multicenter hospital-based cohort study

    NARCIS (Netherlands)

    Kaasch, A. J.; Rieg, S.; Kuetscher, J.; Brodt, H. -R.; Widmann, T.; Herrmann, M.; Meyer, C.; Welte, T.; Kern, P.; Haars, U.; Reuter, S.; Huebner, I.; Strauss, R.; Sinha, B.; Brunkhorst, F. M.; Hellmich, M.; Faetkenheuer, G.; Kern, W. V.; Seifert, H.

    2013-01-01

    Early broad-spectrum antimicrobial treatment reduces mortality in patients with septic shock. In a multicenter, prospective observational study, we explored whether delayed appropriate antimicrobial therapy (AAT) influences outcome in Staphylococcus aureus bloodstream infection (SAB). Two hundred an

  6. Sustained ex vivo skin antiseptic activity of chlorhexidine in poly(epsilon-caprolactone) nanocapsule encapsulated form and as a digluconate.

    Science.gov (United States)

    Lboutounne, Hassan; Chaulet, Jean-François; Ploton, Christine; Falson, Françoise; Pirot, Fabrice

    2002-08-21

    In this work, the sustained bactericidal activity of chlorhexidine base loaded poly(epsilon-caprolactone), PCL, nanocapsules against Staphylococcus epidermidis inoculated onto porcine ear skin was investigated. Drug loaded nanocapsules were prepared by the interfacial polymer deposition following solvent displacement method, then characterized by photon correlation spectroscopy, electrophoretic measurements, transmission and scanning electron microscopy. Antimicrobial activity of these colloidal carriers was evaluated (i) in vitro against eight strains of bacteria, and (ii) ex vivo against Staphylococcus epidermidis inoculated for 12 h onto porcine ear skin surface treated for 3 min either with 0.6% chlorhexidine base loaded or unloaded nanocapsules suspended in hydrogel, or 1% chlorhexidine digluconate aqueous solution. Chlorhexidine absorption into the stratum corneum (SC) was evaluated by the tape-stripping method. The results showed that chlorhexidine nanocapsules in aqueous suspension having a 200-300 nm size and a positive charge exhibited similar minimum inhibitory concentrations against several bacteria with chlorhexidine digluconate aqueous solution. Ex vivo, there was a significant reduction in the number of colony forming units (CFUs) from 3-min treated skin with chlorhexidine nanocapsule suspension (5 to <1 log(10)) compared to chlorhexidine digluconate solution (5 to 2.02 log(10)) after a 8-h artificial contamination. After a 12-h artificial contamination, both formulations failed to achieve a 5 log(10) reduction. Furthermore, from a 3-min treatment with an identical applied dose and a subsequent 12-h artificial contamination, a residual chlorhexidine concentration in the SC was found to be three-fold higher with chlorhexidine nanocapsule suspension than with chlorhexidine digluconate solution. Interestingly, nanocapsules were shown in porcine skin follicles. Consequently, a topical application of chlorhexidine base-loaded positively charged

  7. The investigation of copper-based impregnated activated carbons prepared from water-soluble materials for broad spectrum respirator applications

    International Nuclear Information System (INIS)

    The preparation of impregnated activated carbons (IACs) from aqueous, copper-containing solutions for broad spectrum gas filtration applications is studied here. Several samples were studied to determine the effect that impregnant loading, impregnant distribution and impregnant recipe had on the overall performance. Dynamic flow testing was used to determine the gas filtration capacity of the IAC samples versus a variety of challenge gases. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) were used to characterize the impregnant distribution on the carbon as a function of impregnant loading. Oven tests were performed to determine the thermal stability of the IAC samples exposed to elevated temperatures. The role impregnant distribution plays in gas filtration capacity and the overall performance of the IAC samples is discussed. The IAC samples prepared in this work were found to have gas filtration capacities as good as or better than broad spectrum respirator carbon samples prepared from the patent literature. IACs impregnated with an aqueous 2.4 M Cu(NO3)2/0.04 M H3PO4.12MoO3/4 M HNO3 solution that were heated to 200 deg. C under argon were found to have the best overall performance of the samples studied in this work.

  8. Changes in Cell Viability of Wounded Fibroblasts following Laser Irradiation in Broad-Spectrum or Infrared Light

    International Nuclear Information System (INIS)

    Objective. This study aimed to establish if broad-spectrum or infrared (IR) light in combination with laser therapy can assist phototherapy to improve the cell function of wounded cells. Background. The effect of laser light may be partly or completely reduced by broad-spectrum light. Methods. Wounded human skin fibroblasts were irradiated with 5 J/cm2 using a helium-neon laser, a diode laser, or an Nd:YAG laser in the dark, in the light, or in IR. Changes in cell viability were evaluated by cell morphology, ATP cell viability, LDH membrane integrity, and caspase 3/7 as an early marker of apoptosis. Results. Wounded cells exposed to 5 J/cm2 using 632.8 nm in the dark or 830 nm in the light or 1064 nm in the dark showed an increase in ATP viability, an increase in cytokine expression, and a decrease in LDH cytotoxicity indicating that the metabolic activity of the wounded cells was stimulated. Conclusion. Wounded cells irradiated in IR light showed an undesirable thermal effect that was proportional to the duration of exposure.

  9. The investigation of copper-based impregnated activated carbons prepared from water-soluble materials for broad spectrum respirator applications

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.W.H.; Westreich, P.; Abdellatif, H.; Filbee-Dexter, P.; Smith, A.J. [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, B3H 3J5 (Canada); Wood, T.E. [3M Company, St. Paul, MN, 55144 (United States); Croll, L.M.; Reynolds, J.H. [3M Canada Company, Brockville, Ontario, K6V 5V8 (Canada); Dahn, J.R., E-mail: jeff.dahn@dal.ca [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, B3H 3J5 (Canada); Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, B3H 4J3 (Canada)

    2010-08-15

    The preparation of impregnated activated carbons (IACs) from aqueous, copper-containing solutions for broad spectrum gas filtration applications is studied here. Several samples were studied to determine the effect that impregnant loading, impregnant distribution and impregnant recipe had on the overall performance. Dynamic flow testing was used to determine the gas filtration capacity of the IAC samples versus a variety of challenge gases. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) were used to characterize the impregnant distribution on the carbon as a function of impregnant loading. Oven tests were performed to determine the thermal stability of the IAC samples exposed to elevated temperatures. The role impregnant distribution plays in gas filtration capacity and the overall performance of the IAC samples is discussed. The IAC samples prepared in this work were found to have gas filtration capacities as good as or better than broad spectrum respirator carbon samples prepared from the patent literature. IACs impregnated with an aqueous 2.4 M Cu(NO{sub 3}){sub 2}/0.04 M H{sub 3}PO{sub 4}.12MoO{sub 3}/4 M HNO{sub 3} solution that were heated to 200 deg. C under argon were found to have the best overall performance of the samples studied in this work.

  10. Anti-biofilm Effect of Glass Ionomer Cements Incorporated with Chlorhexidine and Bioaetive Glass

    Institute of Scientific and Technical Information of China (English)

    HUANG Xueqing; YANG Tiantian; ZHAO Suling; HUANG Cui; DU Xijin

    2012-01-01

    The effect of glass ionomer cement and resin-modified glass ionomer cement incorporated with chlorhexidine and bioactive glass on antimicrobial activity and physicochemical properties were investigated.The experimental results showed that groups incorporated with 1% chlorhexidine exhibited a significant reduction of optical density values of the bacterial suspension and increased the degradation of Streptococcus mutans biofilm.However,groups incorporated with 10% bioactive glass did not affect the optical density values and the biofilm formation.The mechanical properties of the materials and the polymerization were not influenced by the addition of chlorhexidine.Nevertheless,the compressive strength was lower when the materials were incorporated with bioactive glass.It can be concluded that glass ionomer cements incorporated with chlorhexidine can maintain its mechanical properties as well as reduce early S mutans biofilm formation.Controlled release/sustained release technology may be required to optimize the antibacterial activity of glass ionomer cements incorporated with bioactive glass.

  11. Broad-spectrum Antibiotic Plus Metronidazole May Not Prevent the Deterioration of Necrotizing Enterocolitis From Stage II to III in Full-term and Near-term Infants: A Propensity Score-matched Cohort Study.

    Science.gov (United States)

    Luo, Li-Juan; Li, Xin; Yang, Kai-Di; Lu, Jiang-Yi; Li, Lu-Quan

    2015-10-01

    Necrotizing enterocolitis (NEC) is the most common and frequently dangerous neonatal gastrointestinal disease. Studies have shown broad-spectrum antibiotics plus anaerobic antimicrobial therapy did not prevent the deterioration of NEC among very low birth preterm infants. However, few studies about this therapy which focused on full-term and near-term infant with NEC has been reported. The aim of this study was to evaluate the effect of broad-spectrum antibiotic plus metronidazole in preventing the deterioration of NEC from stage II to III in full-term and near-term infants.A retrospective cohort study based on the propensity score (PS) 1:1 matching was performed among the full-term and near-term infants with NEC (Bell stage ≥II). All infants who received broad-spectrum antibiotics were divided into 2 groups: group with metronidazole treatment (metronidazole was used ≥4 days continuously, 15 mg/kg/day) and group without metronidazole treatment. The depraved rates of stage II NEC between the 2 groups were compared. Meanwhile, the risk factors associated with the deterioration of stage II NEC were analyzed by case-control study in the PS-matched cases.A total of 229 infants met the inclusion criteria. Before PS-matching, we found the deterioration of NEC rate in the group with metronidazole treatment was higher than that in the group without metronidazole treatment (18.1% [28/155] vs 8.1% [6/74]; P = 0.048). After PS-matching, 73 pairs were matched, and the depraved rate of NEC in the group with metronidazole treatment was not lower than that in the group without metronidazole treatment (15.1% vs 8.2%; P = 0.2). Binary logistic regression analysis showed that sepsis after NEC (odds ratio [OR] 3.748, 95% confidence interval [CI] 1.171-11.998, P = 0.03), the need to use transfusion of blood products after diagnosis of NEC (OR 8.003, 95% CI 2.365-27.087, P = 0.00), and the need of longer time for nasogastric suction were risk factors for stage II NEC progressing to

  12. Antimicrobials for bacterial bioterrorism agents.

    Science.gov (United States)

    Sarkar-Tyson, Mitali; Atkins, Helen S

    2011-06-01

    The limitations of current antimicrobials for highly virulent pathogens considered as potential bioterrorism agents drives the requirement for new antimicrobials that are suitable for use in populations in the event of a deliberate release. Strategies targeting bacterial virulence offer the potential for new countermeasures to combat bacterial bioterrorism agents, including those active against a broad spectrum of pathogens. Although early in the development of antivirulence approaches, inhibitors of bacterial type III secretion systems and cell division mechanisms show promise for the future.

  13. Toxicity modulation, resistance enzyme evasion, and A-site X-ray structure of broad-spectrum antibacterial neomycin analogs.

    Science.gov (United States)

    Maianti, Juan Pablo; Kanazawa, Hiroki; Dozzo, Paola; Matias, Rowena D; Feeney, Lee Ann; Armstrong, Eliana S; Hildebrandt, Darin J; Kane, Timothy R; Gliedt, Micah J; Goldblum, Adam A; Linsell, Martin S; Aggen, James B; Kondo, Jiro; Hanessian, Stephen

    2014-09-19

    Aminoglycoside antibiotics are pseudosaccharides decorated with ammonium groups that are critical for their potent broad-spectrum antibacterial activity. Despite over three decades of speculation whether or not modulation of pKa is a viable strategy to curtail aminoglycoside kidney toxicity, there is a lack of methods to systematically probe amine-RNA interactions and resultant cytotoxicity trends. This study reports the first series of potent aminoglycoside antibiotics harboring fluorinated N1-hydroxyaminobutyryl acyl (HABA) appendages for which fluorine-RNA contacts are revealed through an X-ray cocrystal structure within the RNA A-site. Cytotoxicity in kidney-derived cells was significantly reduced for the derivative featuring our novel β,β-difluoro-HABA group, which masks one net charge by lowering the pKa without compromising antibacterial potency. This novel side-chain assists in evasion of aminoglycoside-modifying enzymes, and it can be easily transferred to impart these properties onto any number of novel analogs.

  14. Comparative analysis of Salmonella susceptibility and tolerance to the biocide chlorhexidine identifies a complex cellular defence network

    OpenAIRE

    SeamusFanning; OrlaCondell; KristianHandler; AineSheridan; KjellSergeant; JUANWANG; JarlathNally

    2014-01-01

    Chlorhexidine is one of the most widely used biocides in health and agricultural settings as well as in the modern food industry. It is a cationic biocide of the biguanide class. Details of its mechanism of action are largely unknown. The frequent use of chlorhexidine has been questioned recently, amidst concerns that an overuse of this compound may select for bacteria displaying an altered susceptibility to antimicrobials, including clinically important anti-bacterial agents. We generat...

  15. An investigation into the role of dendrimers as potential enhancers of the dermal delivery of topically applied chlorhexidine

    OpenAIRE

    Judd, Amy Maryanne

    2013-01-01

    The reduction of bacteria on the skin results in prophylactic and therapeutic benefits by reducing the occurrence of skin infections. Currently, chlorhexidine digluconate, a conventional topical antiseptic, permeates the skin poorly leaving viable opportunistic pathogens below the superficial layers of the stratum corneum. The aim of this study was to use polyamidoamine (PAMAM) dendrimers to enhance the topical delivery of chlorhexidine digluconate to improve its antimicrobial efficacy.

  16. IgE-mediated allergy to chlorhexidine

    DEFF Research Database (Denmark)

    Garvey, Lene Heise; Krøigaard, Mogens; Poulsen, Lars K.;

    2007-01-01

    Investigations at the Danish Anesthesia Allergy Centre have included testing for allergy to chlorhexidine since 1999.......Investigations at the Danish Anesthesia Allergy Centre have included testing for allergy to chlorhexidine since 1999....

  17. Penetration of Chlorhexidine into Human Skin ▿

    OpenAIRE

    Karpanen, T. J.; Worthington, T.; Conway, Barbara R; Hilton, A. C.; Elliott, T. S. J.; Lambert, P A

    2008-01-01

    This study evaluated a model of skin permeation to determine the depth of delivery of chlorhexidine into full-thickness excised human skin following topical application of 2% (wt/vol) aqueous chlorhexidine digluconate. Skin permeation studies were performed on full-thickness human skin using Franz diffusion cells with exposure to chlorhexidine for 2 min, 30 min, and 24 h. The concentration of chlorhexidine extracted from skin sections was determined to a depth of 1,500 µm following serial sec...

  18. 21 CFR 524.402 - Chlorhexidine.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Chlorhexidine. 524.402 Section 524.402 Food and..., FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.402 Chlorhexidine. (a) Specifications. Each gram of ointment contains 10 milligrams chlorhexidine acetate. (b)...

  19. 21 CFR 556.120 - Chlorhexidine.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Chlorhexidine. 556.120 Section 556.120 Food and... Residues of New Animal Drugs § 556.120 Chlorhexidine. A tolerance of zero is established for residues of chlorhexidine in the uncooked edible tissues of calves....

  20. Chlorhexidine allergy due to topical application

    OpenAIRE

    Nandita N Keni; Meena A Aras; Vidya Chitre

    2012-01-01

    Chlorhexidine is commonly used in dentistry in various forms. Allergic reactions to chlorhexidine of both immediate and delayed type have been reported. Although the incidence is low there may be severe manifestations in some patients. This report presents a case of allergy to chlorhexidine following topical application.

  1. Chlorhexidine allergy due to topical application

    Directory of Open Access Journals (Sweden)

    Nandita N Keni

    2012-01-01

    Full Text Available Chlorhexidine is commonly used in dentistry in various forms. Allergic reactions to chlorhexidine of both immediate and delayed type have been reported. Although the incidence is low there may be severe manifestations in some patients. This report presents a case of allergy to chlorhexidine following topical application.

  2. New insights into broad spectrum communities of the Early Holocene Near East: The birds of Hallan Çemi

    Science.gov (United States)

    Zeder, Melinda A.; Spitzer, Megan D.

    2016-11-01

    The Early Holocene in Near East was a pivotal transitional period that witnessed dramatic changes in climate and environment, human settlement, major changes in subsistence strategies focusing on a broad range of different plant and animal resources, and a radical restructuring of social relations. The remarkable corpus of avifauna from the Early Holocene site of Hallan Çemi in southeastern Turkey sheds new light on key issues about this dynamic period that has been termed the "Broad Spectrum Revolution". The avifauna from this important site demonstrate how Hallan Çemi occupants took advantage of the site's strategic location at the junction of multiple environmental zones by extracting a diverse range of seasonally available resources from both near-by and more distant eco-zones to cobble together a stable subsistence economy capable of supporting this small community throughout the year. They give testimony to the impacts of resource utilization over time, especially on species unable to rebound from sustained human hunting. At the same time, they show how Hallan Çemi residents mitigated these impacts by replacing depleted resources with alternative, more resilient ones that could be more sustainably harvested. They open a window onto the growing investment in feasting and ritual activity that helped bind this community together. In so doing they provide a means of empirically evaluating the efficacy of contrasting explanatory frameworks for the Broad Spectrum Revolution that gave rise to the subsequent domestication of plant and animals in the Near East. Contrary to frameworks that cast these developments as responses to resource depression, lessons learned from the Hallan Çemi avifauna lend support to frameworks that emphasize the human capacity to strategically target, capitalize, and improve upon circumscribed resource rich environments in a way that permits more permanent occupation of these niches. And they underscore the degree to which social and

  3. Residual activity of cetrimide and chlorhexidine on Enterococcus faecalis-infected root canals

    Institute of Scientific and Technical Information of China (English)

    Carmen Mara Ferrer-Luque; Mara Teresa Arias-Moliz; Matilde Ruz-Linares; Mara Elena Martnez Garca; Pilar Baca

    2014-01-01

    Effective final irrigation regimen is an important step in order to achieve better disinfection and ensure residual antimicrobial effects after root canal preparation. The aim of this study was to compare the residual antimicrobial activity of 0.2%cetrimide, and 0.2%and 2%chlorhexidine in root canals infected with Enterococcus faecalis. Biofilms of E. faecalis were grown on uniradicular roots for 4 weeks. After root canal preparation, root canals were irrigated with 17%ethylenediaminetetraacetic acid (EDTA) to remove the smear layer. The roots were randomly divided into three experimental groups (n526) according to the final irrigating solution:Group I, 5 mL 0.2%cetrimide;Group II, 5 mL 0.2%chlorhexidine;and Group III, 5 mL 2%chlorhexidine. Samples were collected for 50 days to denote the presence of bacterial growth. The proportion of ungrown specimens over 50 days was evaluated using the nonparametric Kaplan-Meier survival analysis. Differences among groups were tested using the log-rank test and the level of statistical significance was set at P,0.05. The highest survival value was found with 2%chlorhexidine, showing statistically significant differences from the other two groups. At 50 days, E. faecalis growth was detected in 69.23%specimens in Groups I and II, and in 34.61%specimens of Group III. There were no significant differences between 0.2%cetrimide and 0.2%chlorhexidine. Final irrigation with 2%chlorhexidine showed greater residual activity than 0.2%chlorhexidine and 0.2%cetrimide in root canals infected with E. faecalis.

  4. Structures of mammalian ER α-glucosidase II capture the binding modes of broad-spectrum iminosugar antivirals.

    Science.gov (United States)

    Caputo, Alessandro T; Alonzi, Dominic S; Marti, Lucia; Reca, Ida-Barbara; Kiappes, J L; Struwe, Weston B; Cross, Alice; Basu, Souradeep; Lowe, Edward D; Darlot, Benoit; Santino, Angelo; Roversi, Pietro; Zitzmann, Nicole

    2016-08-01

    The biosynthesis of enveloped viruses depends heavily on the host cell endoplasmic reticulum (ER) glycoprotein quality control (QC) machinery. This dependency exceeds the dependency of host glycoproteins, offering a window for the targeting of ERQC for the development of broad-spectrum antivirals. We determined small-angle X-ray scattering (SAXS) and crystal structures of the main ERQC enzyme, ER α-glucosidase II (α-GluII; from mouse), alone and in complex with key ligands of its catalytic cycle and antiviral iminosugars, including two that are in clinical trials for the treatment of dengue fever. The SAXS data capture the enzyme's quaternary structure and suggest a conformational rearrangement is needed for the simultaneous binding of a monoglucosylated glycan to both subunits. The X-ray structures with key catalytic cycle intermediates highlight that an insertion between the +1 and +2 subsites contributes to the enzyme's activity and substrate specificity, and reveal that the presence of d-mannose at the +1 subsite renders the acid catalyst less efficient during the cleavage of the monoglucosylated substrate. The complexes with iminosugar antivirals suggest that inhibitors targeting a conserved ring of aromatic residues between the α-GluII +1 and +2 subsites would have increased potency and selectivity, thus providing a template for further rational drug design. PMID:27462106

  5. A novel alkaloid from marine-derived actinomycete Streptomyces xinghaiensis with broad-spectrum antibacterial and cytotoxic activities.

    Directory of Open Access Journals (Sweden)

    Wence Jiao

    Full Text Available Due to the increasing emergence of drug-resistant bacteria and tumor cell lines, novel antibiotics with antibacterial and cytotoxic activities are urgently needed. Marine actinobacteria are rich sources of novel antibiotics, and here we report the discovery of a novel alkaloid, xinghaiamine A, from a marine-derived actinomycete Streptomyces xinghaiensis NRRL B24674(T. Xinghaiamine A was purified from the fermentation broth, and its structure was elucidated based on extensive spectroscopic analysis, including 1D and 2D NMR spectrum as well as mass spectrometry. Xinghaiamine A was identified to be a novel alkaloid with highly symmetric structure on the basis of sulfoxide functional group, and sulfoxide containing compound has so far never been reported in microorganisms. Biological assays revealed that xinghaiamine A exhibited broad-spectrum antibacterial activities to both Gram-negative persistent hospital pathogens (e.g. Acinetobacter baumannii, Pseudomonas aeruginosa and Escherichia coli and Gram-positive ones, which include Staphylococcus aureus and Bacillus subtilis. In addition, xinghaiamine A also exhibited potent cytotoxic activity to human cancer cell lines of MCF-7 and U-937 with the IC50 of 0.6 and 0.5 µM, respectively.

  6. Comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin and the Hawaiian marine algae, Chaetoceros, for potential broad-spectrum control of anaerobically grown lactic acid bacteria

    Science.gov (United States)

    The gastrointestinal tract of bovines often contains bacteria that contribute to disorders of the rumen and may also contain foodborne or opportunistic human pathogens as well as bacteria capable of causing mastitis in cows. Thus, there is a need to develop broad-spectrum therapies that are effecti...

  7. Draft genome sequence of Streptomyces sp. strain Wb2n-11, a desert isolate with broad-spectrum antagonism against soilborne phytopathogens

    Energy Technology Data Exchange (ETDEWEB)

    Koeberl, Martina; White, Richard A.; Erschen, Sabine; El-Arabi, Tarek F.; Jansson, Janet K.; Berg, Gabriele

    2015-08-06

    Streptomyces sp. strain Wb2n-11, isolated from native desert soil, exhibited broad-spectrum antagonism against plant pathogenic fungi, bacteria and nematodes. The 8.2 Mb draft genome reveals genes putatively responsible for its promising biocontrol activity and genes which enable the soil bacterium to directly interact beneficially with plants.

  8. Broad-spectrum sunscreens prevent the secretion of proinflammatory cytokines in human keratinocytes exposed to ultraviolet A and phototoxic lomefloxacin

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, P.; Cybulski, M. [Lasers and Electro-Optics Div., Consumer and Clinical Radiation Protection Bureau, Product Safety Program, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario (Canada)], E-mail: pascale_reinhardt@hc-sc.gc.ca; Miller, S.M.; Ferrarotto, C.; Wilkins, R. [Radiobiology Div., Consumer and Clinical Radiation Protection Bureau, Product Safety Program, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario (Canada); Deslauriers, Y. [Lasers and Electro-Optics Div., Consumer and Clinical Radiation Protection Bureau, Product Safety Program, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario (Canada)

    2006-02-15

    The combination of phototoxic drugs and ultraviolet (UV) radiation can trigger the release of proinflammatory cytokines. The present study measured the ability of sunscreens to prevent cytokine secretion in human keratinocytes following cotreatment of these cells with a known photoreactive drug and UVA. Keratinocytes were treated for 1 h with increasing concentrations of lomefloxacin (LOM) or norfloxacin (NOR), exposed to 15 J/cm{sup 2} UVA, and incubated for 24 h. NOR, owing to the absence of a fluorine atom in position 8, was non-phototoxic and used as a negative control. Cell viability and the release of 3 cytokines were assessed, namely interleukin-1{alpha} (IL-1{alpha}), interleukin-6 (IL-6), and tumour necrosis factor-{alpha} (TNF-{alpha}). The measurement of these cytokines may be a useful tool for detecting photoreactive compounds. To measure their ability to prevent cytokine secretion, various sunscreens were inserted between the UVA source and the cells. Treatment with NOR, NOR plus UVA, or LOM had no effect on the cells. LOM plus UVA, however, had an effect on cell viability and on cytokine secretion. IL-1{alpha} levels increased with LOM concentration. The release of TNF-{alpha} and IL-6 followed the same pattern at lower concentrations of LOM but peaked at 15 {mu}mol/L and decreased at higher concentrations. Sunscreens protected the cells from the effects of LOM plus UVA, as cell viability and levels of cytokines remained the same as in the control cells. In conclusion, the application of broad-spectrum sunscreen by individuals exposed to UVA radiation may prevent phototoxic reactions initiated by drugs such as LOM. (author)

  9. Reversal of the Progression of Fatal Coronavirus Infection in Cats by a Broad-Spectrum Coronavirus Protease Inhibitor.

    Directory of Open Access Journals (Sweden)

    Yunjeong Kim

    2016-03-01

    Full Text Available Coronaviruses infect animals and humans causing a wide range of diseases. The diversity of coronaviruses in many mammalian species is contributed by relatively high mutation and recombination rates during replication. This dynamic nature of coronaviruses may facilitate cross-species transmission and shifts in tissue or cell tropism in a host, resulting in substantial change in virulence. Feline enteric coronavirus (FECV causes inapparent or mild enteritis in cats, but a highly fatal disease, called feline infectious peritonitis (FIP, can arise through mutation of FECV to FIP virus (FIPV. The pathogenesis of FIP is intimately associated with immune responses and involves depletion of T cells, features shared by some other coronaviruses like Severe Acute Respiratory Syndrome Coronavirus. The increasing risks of highly virulent coronavirus infections in humans or animals call for effective antiviral drugs, but no such measures are yet available. Previously, we have reported the inhibitors that target 3C-like protease (3CLpro with broad-spectrum activity against important human and animal coronaviruses. Here, we evaluated the therapeutic efficacy of our 3CLpro inhibitor in laboratory cats with FIP. Experimental FIP is 100% fatal once certain clinical and laboratory signs become apparent. We found that antiviral treatment led to full recovery of cats when treatment was started at a stage of disease that would be otherwise fatal if left untreated. Antiviral treatment was associated with a rapid improvement in fever, ascites, lymphopenia and gross signs of illness and cats returned to normal health within 20 days or less of treatment. Significant reduction in viral titers was also observed in cats. These results indicate that continuous virus replication is required for progression of immune-mediated inflammatory disease of FIP. These findings may provide important insights into devising therapeutic strategies and selection of antiviral compounds for

  10. Reversal of the Progression of Fatal Coronavirus Infection in Cats by a Broad-Spectrum Coronavirus Protease Inhibitor.

    Science.gov (United States)

    Kim, Yunjeong; Liu, Hongwei; Galasiti Kankanamalage, Anushka C; Weerasekara, Sahani; Hua, Duy H; Groutas, William C; Chang, Kyeong-Ok; Pedersen, Niels C

    2016-03-01

    Coronaviruses infect animals and humans causing a wide range of diseases. The diversity of coronaviruses in many mammalian species is contributed by relatively high mutation and recombination rates during replication. This dynamic nature of coronaviruses may facilitate cross-species transmission and shifts in tissue or cell tropism in a host, resulting in substantial change in virulence. Feline enteric coronavirus (FECV) causes inapparent or mild enteritis in cats, but a highly fatal disease, called feline infectious peritonitis (FIP), can arise through mutation of FECV to FIP virus (FIPV). The pathogenesis of FIP is intimately associated with immune responses and involves depletion of T cells, features shared by some other coronaviruses like Severe Acute Respiratory Syndrome Coronavirus. The increasing risks of highly virulent coronavirus infections in humans or animals call for effective antiviral drugs, but no such measures are yet available. Previously, we have reported the inhibitors that target 3C-like protease (3CLpro) with broad-spectrum activity against important human and animal coronaviruses. Here, we evaluated the therapeutic efficacy of our 3CLpro inhibitor in laboratory cats with FIP. Experimental FIP is 100% fatal once certain clinical and laboratory signs become apparent. We found that antiviral treatment led to full recovery of cats when treatment was started at a stage of disease that would be otherwise fatal if left untreated. Antiviral treatment was associated with a rapid improvement in fever, ascites, lymphopenia and gross signs of illness and cats returned to normal health within 20 days or less of treatment. Significant reduction in viral titers was also observed in cats. These results indicate that continuous virus replication is required for progression of immune-mediated inflammatory disease of FIP. These findings may provide important insights into devising therapeutic strategies and selection of antiviral compounds for further

  11. Exoproteome and secretome derived broad spectrum novel drug and vaccine candidates in Vibrio cholerae targeted by Piper betel derived compounds.

    Directory of Open Access Journals (Sweden)

    Debmalya Barh

    Full Text Available Vibrio cholerae is the causal organism of the cholera epidemic, which is mostly prevalent in developing and underdeveloped countries. However, incidences of cholera in developed countries are also alarming. Because of the emergence of new drug-resistant strains, even though several generic drugs and vaccines have been developed over time, Vibrio infections remain a global health problem that appeals for the development of novel drugs and vaccines against the pathogen. Here, applying comparative proteomic and reverse vaccinology approaches to the exoproteome and secretome of the pathogen, we have identified three candidate targets (ompU, uppP and yajC for most of the pathogenic Vibrio strains. Two targets (uppP and yajC are novel to Vibrio, and two targets (uppP and ompU can be used to develop both drugs and vaccines (dual targets against broad spectrum Vibrio serotypes. Using our novel computational approach, we have identified three peptide vaccine candidates that have high potential to induce both B- and T-cell-mediated immune responses from our identified two dual targets. These two targets were modeled and subjected to virtual screening against natural compounds derived from Piper betel. Seven compounds were identified first time from Piper betel to be highly effective to render the function of these targets to identify them as emerging potential drugs against Vibrio. Our preliminary validation suggests that these identified peptide vaccines and betel compounds are highly effective against Vibrio cholerae. Currently we are exhaustively validating these targets, candidate peptide vaccines, and betel derived lead compounds against a number of Vibrio species.

  12. Baulamycins A and B, broad-spectrum antibiotics identified as inhibitors of siderophore biosynthesis in Staphylococcus aureus and Bacillus anthracis.

    Science.gov (United States)

    Tripathi, Ashootosh; Schofield, Michael M; Chlipala, George E; Schultz, Pamela J; Yim, Isaiah; Newmister, Sean A; Nusca, Tyler D; Scaglione, Jamie B; Hanna, Philip C; Tamayo-Castillo, Giselle; Sherman, David H

    2014-01-29

    Siderophores are high-affinity iron chelators produced by microorganisms and frequently contribute to the virulence of human pathogens. Targeted inhibition of the biosynthesis of siderophores staphyloferrin B of Staphylococcus aureus and petrobactin of Bacillus anthracis hold considerable potential as a single or combined treatment for methicillin-resistant S. aureus (MRSA) and anthrax infection, respectively. The biosynthetic pathways for both siderophores involve a nonribosomal peptide synthetase independent siderophore (NIS) synthetase, including SbnE in staphyloferrin B and AsbA in petrobactin. In this study, we developed a biochemical assay specific for NIS synthetases to screen for inhibitors of SbnE and AsbA against a library of marine microbial-derived natural product extracts (NPEs). Analysis of the NPE derived from Streptomyces tempisquensis led to the isolation of the novel antibiotics baulamycins A (BmcA, 6) and B (BmcB, 7). BmcA and BmcB displayed in vitro activity with IC50 values of 4.8 μM and 19 μM against SbnE and 180 μM and 200 μM against AsbA, respectively. Kinetic analysis showed that the compounds function as reversible competitive enzyme inhibitors. Liquid culture studies with S. aureus , B. anthracis , E. coli , and several other bacterial pathogens demonstrated the capacity of these natural products to penetrate bacterial barriers and inhibit growth of both Gram-positive and Gram-negative species. These studies provide proof-of-concept that natural product inhibitors targeting siderophore virulence factors can provide access to novel broad-spectrum antibiotics, which may serve as important leads for the development of potent anti-infective agents. PMID:24401083

  13. Reduced TiO2-Graphene Oxide Heterostructure As Broad Spectrum-Driven Efficient Water-Splitting Photocatalysts.

    Science.gov (United States)

    Li, Lihua; Yu, Lili; Lin, Zhaoyong; Yang, Guowei

    2016-04-01

    The reduced TiO2-graphene oxide heterostructure as an alternative broad spectrum-driven efficient water splitting photocatalyst has become a really interesting topic, however, its syntheses has many flaws, e.g., tedious experimental steps, time-consuming, small scale production, and requirement of various additives, for example, hydrazine hydrate is widely used as reductant to the reduction of graphene oxide, which is high toxicity and easy to cause the second pollution. For these issues, herein, we reported the synthesis of the reduced TiO2-graphene oxide heterostructure by a facile chemical reduction agent-free one-step laser ablation in liquid (LAL) method, which achieves extended optical response range from ultraviolet to visible and composites TiO2-x (reduced TiO2) nanoparticle and graphene oxide for promoting charge conducting. 30.64% Ti(3+) content in the reduced TiO2 nanoparticles induces the electronic reconstruction of TiO2, which results in 0.87 eV decrease of the band gap for the visible light absorption. TiO2-x-graphene oxide heterostructure achieved drastically increased photocatalytic H2 production rate, up to 23 times with respect to the blank experiment. Furthermore, a maximum H2 production rate was measured to be 16 mmol/h/g using Pt as a cocatalyst under the simulated sunlight irradiation (AM 1.5G, 135 mW/cm(2)), the quantum efficiencies were measured to be 5.15% for wavelength λ = 365 ± 10 nm and 1.84% for λ = 405 ± 10 nm, and overall solar energy conversion efficiency was measured to be 14.3%. These findings provided new insights into the broad applicability of this methodology for accessing fascinate photocatalysts. PMID:26986700

  14. Photomorphogenesis and photoassimilation in soybean and sorghum grown under broad spectrum or blue-deficient light sources

    Science.gov (United States)

    Britz, S. J.; Sager, J. C.; Knott, W. M. (Principal Investigator)

    1990-01-01

    The role of blue light in plant growth and development was investigated in soybean (Glycine max [L.] Merr. cv Williams) and sorghum (Sorghum bicolor [L.] Moench. cv Rio) grown under equal photosynthetic photon fluxes (approximately 500 micromoles per square meter per second) from broad spectrum daylight fluorescent or blue-deficient, narrow-band (589 nanometers) low pressure sodium (LPS) lamps. Between 14 and 18 days after sowing, it was possible to relate adaptations in photosynthesis and leaf growth to dry matter accumulation. Soybean development under LPS light was similar in several respects to that of shaded plants, consistent with an important role for blue light photoreceptors in regulation of growth response to irradiance. Thus, soybeans from LPS conditions partitioned relatively more growth to leaves and maintained higher average leaf area ratios (mean LAR) that compensated lower net assimilation rates (mean NAR). Relative growth rates were therefore comparable to plants from daylight fluorescent lamps. Reductions in mean NAR were matched by lower rates of net photosynthesis (A) on an area basis in the major photosynthetic source (first trifoliolate) leaf. Lower A in soybean resulted from reduced leaf dry matter per unit leaf area, but lower A under LPS conditions in sorghum correlated with leaf chlorosis and reduced total nitrogen (not observed in soybean). In spite of a lower A, mean NAR was larger in sorghum from LPS conditions, resulting in significantly greater relative growth rates (mean LAR was approximately equal for both light conditions). Leaf starch accumulation rate was higher for both species and starch content at the end of the dark period was elevated two- and three-fold for sorghum and soybean, respectively, under LPS conditions. Possible relations between starch accumulation, leaf export, and plant growth in response to spectral quality were considered.

  15. Controlled delivery of a new broad spectrum antibacterial agent against colitis: In vitro and in vivo performance.

    Science.gov (United States)

    Nieto-Bobadilla, M S; Siepmann, F; Djouina, M; Dubuquoy, L; Tesse, N; Willart, J-F; Dubreuil, L; Siepmann, J; Neut, C

    2015-10-01

    Coated pellets and mini-tablets were prepared containing a new broad spectrum antibacterial agent: CIN-102, a well-defined, synergistic blend of trans-cinnamaldehyde, trans-2-methoxycinnamaldehyde, cinnamyl acetate, linalool, β-caryophyllene, cineol and benzyl benzoate. The aim was to provide a new treatment method for colitis, especially for Inflammatory Bowel Disease (IBD) patients. Since the simple oral gavage of CIN-102 was not able to reduce the pathogenic bacteria involved in colitis (rat model), the drug was incorporated into multiparticulates. The idea was to minimize undesired drug release in the upper gastrointestinal tract and to control CIN-102 release in the colon, in order to optimize the resulting antibiotic concentration at the site of action. A particular challenge was the fact that CIN-102 is a volatile hydrophobic liquid. Pellet cores were prepared by extrusion-spheronization and coated with polymer blends, which are sensitive to colonic bacterial enzymes. Mini-tablets were prepared by direct compression. The release of the main compound of CIN-102 (cinnamaldehyde, 86.7% w/w) was monitored in vitro. Optimized coated pellets and mini-tablets were also tested in vivo: in seven-week-old, male mice suffering from dextran sodium sulfate induced colitis. Importantly, both types of multiparticulates were able: (i) to significantly reduce the number of luminal and mucosal enterobacteria in the mice (the levels of which are increased in the disease state), and (ii) to improve the clinical course of the intestinal inflammation (decrease in the percentages of mice with bloody stools and diarrhea). Thus, the proposed coated pellets and matrix mini-tablets allowing for controlled CIN-102 release show a promising potential for new treatment methods of colitis. PMID:26209123

  16. Isolation of chlorhexidine-resistant Pseudomonas aeruginosa from clinical lesions.

    OpenAIRE

    Nakahara, H; Kozukue, H

    1982-01-01

    The chlorhexidine resistance of 317 strains of Pseudomonas aeruginosa isolated from hospital patients was determined. The distribution pattern of their susceptibility to chlorhexidine clearly revealed two peaks, and the frequency of resistance to chlorhexidine was 84.2%.

  17. Neomycin-phenolic conjugates: polycationic amphiphiles with broad-spectrum antibacterial activity, low hemolytic activity and weak serum protein binding.

    Science.gov (United States)

    Findlay, Brandon; Zhanel, George G; Schweizer, Frank

    2012-02-15

    Here we present a proof-of-concept study, combining two known antimicrobial agents into a hybrid structure in order to develop an emergent cationic detergent-like interaction with the bacterial membrane. Six amphiphilic conjugates were prepared by copper (I)-catalyzed 1,3-dipolar cycloaddition between a neomycin B-derived azide and three alkyne-modified phenolic disinfectants. Three conjugates displayed good activity against a variety of clinically relevant Gram positive and Gram negative bacteria, including MRSA, without the high level of hemolysis or strong binding to serum proteins commonly observed with other cationic antimicrobial peptides and detergents.

  18. Comparative analysis of Salmonella susceptibility and tolerance to the biocide chlorhexidine identifies a complex cellular defence network

    Directory of Open Access Journals (Sweden)

    Orla eCondell

    2014-08-01

    Full Text Available Chlorhexidine is one of the most widely used biocides in health and agricultural settings as well as in the modern food industry. It is a cationic biocide of the biguanide class. Details of its mechanism of action are largely unknown. The frequent use of chlorhexidine has been questioned recently, amidst concerns that an overuse of this compound may select for bacteria displaying an altered susceptibility to antimicrobials, including clinically important anti-bacterial agents.We generated a Salmonella enterica serovar Typhimurium isolate (ST24CHX that exhibited a high-level tolerant phenotype to chlorhexidine, following several rounds of in vitro selection, using sub-lethal concentrations of the biocide. This mutant showed altered suceptibility to a panel of clinically important antimicrobial compounds. Here we describe a genomic, transcriptomic, proteomic, and phenotypic analysis of the chlorhexidine tolerant S. Typhimurium compared with its isogenic sensitive progenitor. Results from this study describe a chlorhexidine defence network that functions in both the reference chlorhexidine sensitive isolate and the tolerant mutant. The defence network involved multiple cell targets including those associated with the synthesis and modification of the cell wall, the SOS response, virulence, and a shift in cellular metabolism towards anoxic pathways, some of which were regulated by CreB and Fur. In addition, results indicated that chlorhexidine tolerance was associated with more extensive modifications of the same cellular processes involved in this proposed network, as well as a divergent defence response involving the up-regulation of additional targets such as the flagellar apparatus and an altered cellular phosphate metabolism.These data show that sub-lethal concentrations of chlorhexidine induce distinct changes in exposed Salmonella, and our findings provide insights into the mechanisms of action and tolerance to this biocidal agent.

  19. Chlorhexidine Preserves Dentin Bond in vitro

    OpenAIRE

    Carrilho, M. R. O.; Carvalho, R. M.; de Goes, M. F.; di Hipólito, V.; Geraldeli, S.; Tay, F.R.; Pashley, D.H.; Tjäderhane, L.

    2007-01-01

    Loss of hybrid layer integrity compromises resin-dentin bond stability. Matrix metalloproteinases (MMPs) may be partially responsible for hybrid layer degradation. Since chlorhexidine inhibits MMPs, we hypothesized that chlorhexidine would decelerate the loss of resin-dentin bonds. Class I preparations in extracted third molars were sectioned into two halves. One half was customarily restored (etch-and-rinse adhesive/resin composite), and the other was treated with 2% chlorhexidine after bein...

  20. Chlorhexidine-containing chewing gum. Clinical documentation

    OpenAIRE

    Imfeld, T

    2006-01-01

    A clinical documentation on chlorhexidine containing chewing gum is presented on the occasion of the launch of CHewX, a chewing gum containing 5 mg of chlorhexidine diacetate in Switzerland. Following an overview on functional chewing gum, the mechanism of action of chlorhexidine (CHX), its toxicity and safety are summarized and a review of clinical studies performed with CHX-containing chewing gum given. Indication, dosage, precautions and benefits of CHX chewing gum are described.

  1. Broad-spectrum matrix metalloproteinase inhibition curbs inflammation and liver injury but aggravates experimental liver fibrosis in mice.

    Directory of Open Access Journals (Sweden)

    Vincent E de Meijer

    Full Text Available BACKGROUND: Liver fibrosis is characterized by excessive synthesis of extracellular matrix proteins, which prevails over their enzymatic degradation, primarily by matrix metalloproteinases (MMPs. The effect of pharmacological MMP inhibition on fibrogenesis, however, is largely unexplored. Inflammation is considered a prerequisite and important co-contributor to fibrosis and is, in part, mediated by tumor necrosis factor (TNF-alpha-converting enzyme (TACE. We hypothesized that treatment with a broad-spectrum MMP and TACE-inhibitor (Marimastat would ameliorate injury and inflammation, leading to decreased fibrogenesis during repeated hepatotoxin-induced liver injury. METHODOLOGY/PRINCIPAL FINDINGS: Liver fibrosis was induced in mice by repeated carbon tetrachloride (CCl4 administration, during which the mice received either Marimastat or vehicle twice daily. A single dose of CCl4 was administered to investigate acute liver injury in mice pretreated with Marimastat, mice deficient in Mmp9, or mice deficient in both TNF-alpha receptors. Liver injury was quantified by alanine aminotransferase (ALT levels and confirmed by histology. Hepatic collagen was determined as hydroxyproline, and expression of fibrogenesis and fibrolysis-related transcripts was determined by quantitative reverse-transcription polymerase chain reaction. Marimastat-treated animals demonstrated significantly attenuated liver injury and inflammation but a 25% increase in collagen deposition. Transcripts related to fibrogenesis were significantly less upregulated compared to vehicle-treated animals, while MMP expression and activity analysis revealed efficient pharmacologic MMP-inhibition and decreased fibrolysis following Marimastat treatment. Marimastat pre-treatment significantly attenuated liver injury following acute CCl4-administration, whereas Mmp9 deficient animals demonstrated no protection. Mice deficient in both TNF-alpha receptors exhibited an 80% reduction of serum ALT

  2. Antimicrobial and antifouling hydrogels formed in situ from polycarbonate and poly(ethylene glycol) via Michael addition.

    Science.gov (United States)

    Liu, Shao Qiong; Yang, Chuan; Huang, Yuan; Ding, Xin; Li, Yan; Fan, Wei Min; Hedrick, James L; Yang, Yi-Yan

    2012-12-18

    A novel class of antimicrobial cationic polycarbonate/PEG hydrogels are designed and synthesized by Michael addition chemistry. These hydrogels demonstrate strong broad-spectrum antimicrobial activities against various clinically isolated multidrug-resistant microbes. Moreover, they exhibit nonfouling properties and prevent the substrate from microbial adhesion. These antimicrobial and antifouling gels are promising materials as catheter coatings and wound dressings to prevent infections.

  3. Control of Streptococcus sanguinis oral biofilm by novel chlorhexidine-chitosan mouthwash: an in vitro study

    OpenAIRE

    Bangalore V. Karthikeyan; K. Selvan Arul; Munivenkatappa V. L. Prabhuji; Vilasan Archana

    2013-01-01

    Objective: The most common prevalent infectious oral diseases in humans are caries and periodontal diseases, which are usually associated with dental plaque. The present in vitro study was designed to evaluate and compare the impact of new mouthwash formulation consisting of chlorhexidine (0.1%) and bioadhesive chitosan (0.5%) on dental plaque bacterial reduction, to that of chlorhexidine or chitosan alone. Methods: In this study, we analyzed the antimicrobial susceptibility of strains of Str...

  4. Stepwise design, synthesis, and in vitro antifungal screening of (Z)-substituted-propenoic acid derivatives with potent broad-spectrum antifungal activity

    OpenAIRE

    Khedr MA

    2015-01-01

    Mohammed A KhedrDepartment of Pharmaceutical Chemistry, Faculty of Pharmacy, Helwan University, Cairo, EgyptAbstract: Fungal infections are a main reason for the high mortality rate worldwide. It is a challenge to design selective antifungal agents with broad-spectrum activity. Lanosterol 14α-demethylase is an attractive target in the design of antifungal agents. Seven compounds were selected from a number of designed compounds using a rational docking study. These compounds were sy...

  5. Proteasome Accessory Factor C (pafC) Is a novel gene Involved in Mycobacterium Intrinsic Resistance to broad-spectrum antibiotics - Fluoroquinolones

    OpenAIRE

    Qiming Li; Longxiang Xie; Quanxin Long; Jinxiao Mao; Hui Li; Mingliang Zhou; Jianping Xie

    2015-01-01

    Antibiotics resistance poses catastrophic threat to global public health. Novel insights into the underlying mechanisms of action will inspire better measures to control drug resistance. Fluoroquinolones are potent and widely prescribed broad-spectrum antibiotics. Bacterial protein degradation pathways represent novel druggable target for the development of new classes of antibiotics. Mycobacteria proteasome accessory factor C (pafC), a component of bacterial proteasome, is involved in fluoro...

  6. Rice RING protein OSBBI1 with E3 ligase activity confers broad-spectrum resistance against Magnaporthe oryzae by modifying the cell wall defence

    Institute of Scientific and Technical Information of China (English)

    Wei Li; Zuhua He; Sihui Zhong; Guojun Li; Qun Li; Bizeng Mao; Yiwen Deng; Huijuan Zhang; Longjun Zeng; Fengming Song

    2011-01-01

    Emerging evidence suggests that E3 ligases play critical roles in diverse biological processes, including innate immune responses in plants. However, the mechanism of the E3 ligase involvement in plant innate immunity is unclear.We report that a rice gene, OsBBI1, encoding a RING finger protein with E3 ligase activity, mediates broad-spectrum disease resistance. The expression of OSBBI1 was induced by rice blast fungus Magnaporthe oryzae, as well as chemical inducers, benzothiadiazole and salicylic acid. Biochemical analysis revealed that OsBBI1 protein possesses E3ubiquitin ligase activity in vitro. Genetic analysis revealed that the loss of OsBBI1 function in a Tos17-insertion line increased susceptibility, while the overexpression of OsBBI1 in transgenic plants conferred enhanced resistance to multiple races of M.oryzae. This indicates that OsBBI1 modulates broad-spectrum resistance against the blast fungus. The OsBBII-overexpressing plants showed higher levels of H,O, accumulation in cells and higher levels of phenolic compounds and cross-linking of proteins in cell walls at infection sites by M. Oryzae compared with wild-type(WT)plants. The cell walls were thicker in the OsBB11-overexpressing plants and thinner in the mutant plants than in the WT plants. Our results suggest that OsBBH modulates broad-spectrum resistance to blast fungus by modifying cell wall defence responses. The functional characterization of OsBBI1 provides insight into the E3 ligase-mediated innate immunity, and a practical tool for constructing broad-spectrum resistance against the most destructive disease in rice.

  7. Treatment Modalities and Antimicrobial Stewardship Initiatives in the Management of Intra-Abdominal Infections

    Directory of Open Access Journals (Sweden)

    Charles Hoffmann

    2016-02-01

    Full Text Available Antimicrobial stewardship programs (ASPs focus on improving the utilization of broad spectrum antibiotics to decrease the incidence of multidrug-resistant Gram positive and Gram negative pathogens. Hospital admission for both medical and surgical intra-abdominal infections (IAIs commonly results in the empiric use of broad spectrum antibiotics such as fluoroquinolones, beta-lactam beta-lactamase inhibitors, and carbapenems that can select for resistant organisms. This review will discuss the management of uncomplicated and complicated IAIs as well as highlight stewardship initiatives focusing on the proper use of broad spectrum antibiotics.

  8. Czech ethanol-free propolis extract displays inhibitory activity against a broad spectrum of bacterial and fungal pathogens.

    Science.gov (United States)

    Netíková, Ladislava; Bogusch, Petr; Heneberg, Petr

    2013-09-01

    Propolis acts primarily as a biocide against invasive bacteria and fungi in the hive, suggesting its potential for industrial applications. In food application, propolis is considered as a chemical preservative in meat products, extending shelf life of frozen meat and other food. The mechanism of action is still unclear due to the synergy of multiple compounds contained in propolis and due to parallel targeting of multiple pathways within each affected organism. Here, we examined the antimicrobial properties of dimethylsulfoxide (DMSO) Czech propolis extract. Until recently, DMSO was only rarely used in the propolis studies, although the other solvents tested (mostly ethanol) may significantly affect the observed inhibitory effects, notwithstanding the antimicrobial effects of ethanol itself. Here, we provide results of zone inhibition tests against Aspergillus fumigatus, Microsporum gypseum, Microsporum canis, Candida albicans, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis. Although we determined inhibitory effects against all the microorganisms tested, the dose-dependent response curves were not similar to each other. While inhibitory effects against C. albicans or S. aureus were strictly dose-dependent, responses of M. gypseum and E. faecalis displayed plateau across the broad range of concentrations tested. Interestingly, response of E. coli revealed the double-peak dose-dependent curve, and responses of M. canis and L. monocytogenes decreased at the highest concentrations tested. Suggested is evaluation of DMSO propolis extracts in experimental treatment of human and veterinary infections, preferably in multitherapy with antibiotics. PMID:23915150

  9. Czech ethanol-free propolis extract displays inhibitory activity against a broad spectrum of bacterial and fungal pathogens.

    Science.gov (United States)

    Netíková, Ladislava; Bogusch, Petr; Heneberg, Petr

    2013-09-01

    Propolis acts primarily as a biocide against invasive bacteria and fungi in the hive, suggesting its potential for industrial applications. In food application, propolis is considered as a chemical preservative in meat products, extending shelf life of frozen meat and other food. The mechanism of action is still unclear due to the synergy of multiple compounds contained in propolis and due to parallel targeting of multiple pathways within each affected organism. Here, we examined the antimicrobial properties of dimethylsulfoxide (DMSO) Czech propolis extract. Until recently, DMSO was only rarely used in the propolis studies, although the other solvents tested (mostly ethanol) may significantly affect the observed inhibitory effects, notwithstanding the antimicrobial effects of ethanol itself. Here, we provide results of zone inhibition tests against Aspergillus fumigatus, Microsporum gypseum, Microsporum canis, Candida albicans, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis. Although we determined inhibitory effects against all the microorganisms tested, the dose-dependent response curves were not similar to each other. While inhibitory effects against C. albicans or S. aureus were strictly dose-dependent, responses of M. gypseum and E. faecalis displayed plateau across the broad range of concentrations tested. Interestingly, response of E. coli revealed the double-peak dose-dependent curve, and responses of M. canis and L. monocytogenes decreased at the highest concentrations tested. Suggested is evaluation of DMSO propolis extracts in experimental treatment of human and veterinary infections, preferably in multitherapy with antibiotics.

  10. Comparison of antimicrobial substantivity of root canal irrigants in instrumented root canals up to 72 h: An in vitro study

    OpenAIRE

    M N Shahani; Subba Reddy, V. V.

    2011-01-01

    Disinfection of the root canal system is one of the primary aims of root canal treatment. This can be achieved through the use of various antimicrobial agents in the form of irrigants and medicaments. The antimicrobial substantivity of 2% chlorhexidine gluconate, 1% povidone iodine, 2.5% hydrogen peroxide followed by 2% sodium hypochlorite, and 2% sodium hypochlorite alone as irrigants was assessed in instrumented root canals. 2% chlorhexidine showed antimicrobial substantivity lasting up to ...

  11. Percutaneous absorption of chlorhexidine in neonatal cord care.

    OpenAIRE

    Aggett, P J; Cooper, L. V.; Ellis, S H; McAinsh, J

    1981-01-01

    The percutaneous absorption of chlorhexidine during its routine use in topical antiseptic preparations used in umbilical cord care was investigated by determining plasma chlorhexidine concentrations at ages 5 and 9 days. These showed that percutaneous absorption of chlorhexidine occurred in preterm neonates treated with a 1% solution of chlorhexidine in ethanol, but not in term infants similarly treated, or in preterm infants treated only with a dusting powder containing 1% chlorhexidine and ...

  12. Complete Genome Sequence of Paenibacillus polymyxa SC2, a Strain of Plant Growth-Promoting Rhizobacterium with Broad-Spectrum Antimicrobial Activity ▿

    OpenAIRE

    Ma, Mingchao; Wang, Cuicui; Ding, Yanqin; Li, Li; Shen, Delong; Jiang, Xin; Guan, Dawei; Cao, Fengming; Chen, Huijun; Feng, Ruihua; Wang, Xuan; Ge, Yifan; Yao, Liangtong; Bing, Xiaohui; Yang, Xiaohong

    2010-01-01

    Paenibacillus polymyxa SC2 is an important plant growth-promoting rhizobacterium (PGPR). Here, we report the complete genome sequence of P. polymyxa SC2. Multiple sets of functional genes have been found in the genome. As far as we know, this is the first complete genome sequence of Paenibacillus polymyxa.

  13. Molecular target of synthetic antimicrobial oligomer in bacterial membranes

    Science.gov (United States)

    Yang, Lihua; Gordon, Vernita; Som, Abhigyan; Cronan, John; Tew, Gregory; Wong, Gerard

    2008-03-01

    Antimicrobial peptides comprises a key component of innate immunity for a wide range of multicellular organisms. It has been shown that natural antimicrobial peptides and their synthetic analogs have demonstrated broad-spectrum antimicrobial activity via permeating bacterial membranes selectively. Synthetic antimicrobials with tunable structure and toxicological profiles are ideal for investigations of selectivity mechanisms. We investigate interactions and self-assembly using a prototypical family of antimicrobials based on phenylene ethynylene. Results from synchrotron small angle x-ray scattering (SAXS) results and in vitro microbicidal assays on genetically modified `knock-out' bacteria will be presented.

  14. Tricyclic GyrB/ParE (TriBE inhibitors: a new class of broad-spectrum dual-targeting antibacterial agents.

    Directory of Open Access Journals (Sweden)

    Leslie W Tari

    Full Text Available Increasing resistance to every major class of antibiotics and a dearth of novel classes of antibacterial agents in development pipelines has created a dwindling reservoir of treatment options for serious bacterial infections. The bacterial type IIA topoisomerases, DNA gyrase and topoisomerase IV, are validated antibacterial drug targets with multiple prospective drug binding sites, including the catalytic site targeted by the fluoroquinolone antibiotics. However, growing resistance to fluoroquinolones, frequently mediated by mutations in the drug-binding site, is increasingly limiting the utility of this antibiotic class, prompting the search for other inhibitor classes that target different sites on the topoisomerase complexes. The highly conserved ATP-binding subunits of DNA gyrase (GyrB and topoisomerase IV (ParE have long been recognized as excellent candidates for the development of dual-targeting antibacterial agents with broad-spectrum potential. However, to date, no natural product or small molecule inhibitors targeting these sites have succeeded in the clinic, and no inhibitors of these enzymes have yet been reported with broad-spectrum antibacterial activity encompassing the majority of Gram-negative pathogens. Using structure-based drug design (SBDD, we have created a novel dual-targeting pyrimidoindole inhibitor series with exquisite potency against GyrB and ParE enzymes from a broad range of clinically important pathogens. Inhibitors from this series demonstrate potent, broad-spectrum antibacterial activity against Gram-positive and Gram-negative pathogens of clinical importance, including fluoroquinolone resistant and multidrug resistant strains. Lead compounds have been discovered with clinical potential; they are well tolerated in animals, and efficacious in Gram-negative infection models.

  15. Targeting N-Glycan Cryptic Sugar Moieties for Broad-Spectrum Virus Neutralization: Progress in Identifying Conserved Molecular Targets in Viruses of Distinct Phylogenetic Origins

    Directory of Open Access Journals (Sweden)

    Denong Wang

    2015-03-01

    Full Text Available Identifying molecular targets for eliciting broadly virus-neutralizing antibodies is one of the key steps toward development of vaccines against emerging viral pathogens. Owing to genomic and somatic diversities among viral species, identifying protein targets for broad-spectrum virus neutralization is highly challenging even for the same virus, such as HIV-1. However, viruses rely on host glycosylation machineries to synthesize and express glycans and, thereby, may display common carbohydrate moieties. Thus, exploring glycan-binding profiles of broad-spectrum virus-neutralizing agents may provide key information to uncover the carbohydrate-based virus-neutralizing epitopes. In this study, we characterized two broadly HIV-neutralizing agents, human monoclonal antibody 2G12 and Galanthus nivalis lectin (GNA, for their viral targeting activities. Although these agents were known to be specific for oligomannosyl antigens, they differ strikingly in virus-binding activities. The former is HIV-1 specific; the latter is broadly reactive and is able to neutralize viruses of distinct phylogenetic origins, such as HIV-1, severe acute respiratory syndrome coronavirus (SARS-CoV, and human cytomegalovirus (HCMV. In carbohydrate microarray analyses, we explored the molecular basis underlying the striking differences in the spectrum of anti-virus activities of the two probes. Unlike 2G12, which is strictly specific for the high-density Man9GlcNAc2Asn (Man9-clusters, GNA recognizes a number of N-glycan cryptic sugar moieties. These include not only the known oligomannosyl antigens but also previously unrecognized tri-antennary or multi-valent GlcNAc-terminating N-glycan epitopes (Tri/m-Gn. These findings highlight the potential of N-glycan cryptic sugar moieties as conserved targets for broad-spectrum virus neutralization and suggest the GNA-model of glycan-binding warrants focused investigation.

  16. 骆驼蓬灵单独和与洗必泰联合对抗金黄色葡萄球菌悬浮菌和生物膜的抗菌活性研究%Antimicrobial Efficacy of Harmaline Alone and in Combination with Chlorhexidine Digluconate against Clinical Isolates of Staphylococcus aureus Grown in Planktonic and Biofilm Cultures

    Institute of Scientific and Technical Information of China (English)

    申凤鸽; 邢明勋; 刘丽慧; 袁鹏; 史祺云; 于录

    2011-01-01

    采用微量稀释法测骆驼蓬灵和洗必泰(CHG)单独抗金黄色葡萄球菌悬浮菌和生物膜的最小抑菌浓度(MIC)和最小杀菌浓度(MBC);棋盘稀释法测定两种药物联合时的协同效果;以及激光共聚焦采集图片检测部分联合的效果.结果表明,骆驼蓬灵和CHG联合具有协同抗菌效果.在悬浮菌试验中,9株显示抗浮游菌协同活性,在生物膜试验中,11株显示协同抗生物膜活性.其余菌株显示相加活性,本试验中无颉颃作用.初步探索了体外试验协同作用的原因,为克服金黄色葡萄球菌耐药提供了一个可供选择的方法.%Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of harmaline and chlorhexidine digluconate (CHG) against clinical isolates of Staphylococcus aureus were determined for each microorganism grown in suspension or biofilm using microbroth dilution method. Chequerboard assays were used to determine synergistic, indifferent or antagonistic interactions between harmaline and CHG; and some of the results were verified by confocal laser scanning microscopy. Harmaline and CHG showed effective antimicrobial activity against suspensions and biofilm cultures of S. aureus. Synergistic antimicrobial effects between harmaline and CHG were observed in 9 and 11 of the 13 S. aureus strains when in suspension and in biofilm, respectively. No antagonistic activity was observed in any of the strains tested. Synergistic activity of harmaline and CHG against clinical isolates of S. aureus (in suspension and in biofilm) were observed in vitro. This study might provide alternative methods to reduce the resistance of S. aureus both in suspension and biofilm.

  17. Comparison of antimicrobial substantivity of root canal irrigants in instrumented root canals up to 72 h: An in vitro study

    Directory of Open Access Journals (Sweden)

    M N Shahani

    2011-01-01

    Full Text Available Disinfection of the root canal system is one of the primary aims of root canal treatment. This can be achieved through the use of various antimicrobial agents in the form of irrigants and medicaments. The antimicrobial substantivity of 2% chlorhexidine gluconate, 1% povidone iodine, 2.5% hydrogen peroxide followed by 2% sodium hypochlorite, and 2% sodium hypochlorite alone as irrigants was assessed in instrumented root canals. 2% chlorhexidine showed antimicrobial substantivity lasting up to 72 h, followed by 1% povidone iodine, and 2% sodium hypochlorite. Thus 2% chlorhexidine should be used as a final rinse irrigant in endodontic treatment protocols.

  18. Tenascin-C is an innate broad-spectrum, HIV-1–neutralizing protein in breast milk

    Science.gov (United States)

    Fouda, Genevieve G.; Jaeger, Frederick H.; Amos, Joshua D.; Ho, Carrie; Kunz, Erika L.; Anasti, Kara; Stamper, Lisa W.; Liebl, Brooke E.; Barbas, Kimberly H.; Ohashi, Tomoo; Moseley, Martin Arthur; Liao, Hua-Xin; Erickson, Harold P.; Alam, S. Munir; Permar, Sallie R.

    2013-01-01

    Achieving an AIDS-free generation will require elimination of postnatal transmission of HIV-1 while maintaining the nutritional and immunologic benefits of breastfeeding for infants in developing regions. Maternal/infant antiretroviral prophylaxis can reduce postnatal HIV-1 transmission, yet toxicities and the development of drug-resistant viral strains may limit the effectiveness of this strategy. Interestingly, in the absence of antiretroviral prophylaxis, greater than 90% of infants exposed to HIV-1 via breastfeeding remain uninfected, despite daily mucosal exposure to the virus for up to 2 y. Moreover, milk of uninfected women inherently neutralizes HIV-1 and prevents virus transmission in animal models, yet the factor(s) responsible for this anti-HIV activity is not well-defined. In this report, we identify a primary HIV-1–neutralizing protein in breast milk, Tenascin-C (TNC). TNC is an extracellular matrix protein important in fetal development and wound healing, yet its antimicrobial properties have not previously been established. Purified TNC captured and neutralized multiclade chronic and transmitted/founder HIV-1 variants, and depletion of TNC abolished the HIV-1–neutralizing activity of milk. TNC bound the HIV-1 Envelope protein at a site that is induced upon engagement of its primary receptor, CD4, and is blocked by V3 loop- (19B and F39F) and chemokine coreceptor binding site-directed (17B) monoclonal antibodies. Our results demonstrate the ability of an innate mucosal host protein found in milk to neutralize HIV-1 via binding to the chemokine coreceptor site, potentially explaining why the majority of HIV-1–exposed breastfed infants are protected against mucosal HIV-1 transmission. PMID:24145401

  19. Broad spectrum antibacterial and antifungal polymeric paint materials: synthesis, structure-activity relationship, and membrane-active mode of action.

    Science.gov (United States)

    Hoque, Jiaul; Akkapeddi, Padma; Yadav, Vikas; Manjunath, Goutham B; Uppu, Divakara S S M; Konai, Mohini M; Yarlagadda, Venkateswarlu; Sanyal, Kaustuv; Haldar, Jayanta

    2015-01-28

    Microbial attachment and subsequent colonization onto surfaces lead to the spread of deadly community-acquired and hospital-acquired (nosocomial) infections. Noncovalent immobilization of water insoluble and organo-soluble cationic polymers onto a surface is a facile approach to prevent microbial contamination. In the present study, we described the synthesis of water insoluble and organo-soluble polymeric materials and demonstrated their structure-activity relationship against various human pathogenic bacteria including drug-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and beta lactam-resistant Klebsiella pneumoniae as well as pathogenic fungi such as Candida spp. and Cryptococcus spp. The polymer coated surfaces completely inactivated both bacteria and fungi upon contact (5 log reduction with respect to control). Linear polymers were more active and found to have a higher killing rate than the branched polymers. The polymer coated surfaces also exhibited significant activity in various complex mammalian fluids such as serum, plasma, and blood and showed negligible hemolysis at an amount much higher than minimum inhibitory amounts (MIAs). These polymers were found to have excellent compatibility with other medically relevant polymers (polylactic acid, PLA) and commercial paint. The cationic hydrophobic polymer coatings disrupted the lipid membrane of both bacteria and fungi and thus showed a membrane-active mode of action. Further, bacteria did not develop resistance against these membrane-active polymers in sharp contrast to conventional antibiotics and lipopeptides, thus the polymers hold great promise to be used as coating materials for developing permanent antimicrobial paint. PMID:25541751

  20. Broad-spectrum inhibition of HIV-1 by a monoclonal antibody directed against a gp120-induced epitope of CD4.

    Directory of Open Access Journals (Sweden)

    Samuele E Burastero

    Full Text Available To penetrate susceptible cells, HIV-1 sequentially interacts with two highly conserved cellular receptors, CD4 and a chemokine receptor like CCR5 or CXCR4. Monoclonal antibodies (MAbs directed against such receptors are currently under clinical investigation as potential preventive or therapeutic agents. We immunized Balb/c mice with molecular complexes of the native, trimeric HIV-1 envelope (Env bound to a soluble form of the human CD4 receptor. Sera from immunized mice were found to contain gp120-CD4 complex-enhanced antibodies and showed broad-spectrum HIV-1-inhibitory activity. A proportion of MAbs derived from these mice preferentially recognized complex-enhanced epitopes. In particular, a CD4-specific MAb designated DB81 (IgG1Κ was found to preferentially bind to a complex-enhanced epitope on the D2 domain of human CD4. MAb DB81 also recognized chimpanzee CD4, but not baboon or macaque CD4, which exhibit sequence divergence in the D2 domain. Functionally, MAb DB81 displayed broad HIV-1-inhibitory activity, but it did not exert suppressive effects on T-cell activation in vitro. The variable regions of the heavy and light chains of MAb DB81 were sequenced. Due to its broad-spectrum anti-HIV-1 activity and lack of immunosuppressive effects, a humanized derivative of MAb DB81 could provide a useful complement to current preventive or therapeutic strategies against HIV-1.

  1. Nanoparticle-encapsulated chlorhexidine against oral bacterial biofilms.

    Directory of Open Access Journals (Sweden)

    Chaminda Jayampath Seneviratne

    Full Text Available BACKGROUND: Chlorhexidine (CHX is a widely used antimicrobial agent in dentistry. Herein, we report the synthesis of a novel mesoporous silica nanoparticle-encapsulated pure CHX (Nano-CHX, and its mechanical profile and antimicrobial properties against oral biofilms. METHODOLOGY/PRINCIPAL FINDINGS: The release of CHX from the Nano-CHX was characterized by UV/visible absorption spectroscopy. The antimicrobial properties of Nano-CHX were evaluated in both planktonic and biofilm modes of representative oral pathogenic bacteria. The Nano-CHX demonstrated potent antibacterial effects on planktonic bacteria and mono-species biofilms at the concentrations of 50-200 µg/mL against Streptococcus mutans, Streptococcus sobrinus, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Enterococccus faecalis. Moreover, Nano-CHX effectively suppressed multi-species biofilms such as S. mutans, F. nucleatum, A. actinomycetemcomitans and Porphyromonas gingivalis up to 72 h. CONCLUSIONS/SIGNIFICANCE: This pioneering study demonstrates the potent antibacterial effects of the Nano-CHX on oral biofilms, and it may be developed as a novel and promising anti-biofilm agent for clinical use.

  2. Synthesis and Characterization of New Chlorhexidine-Containing Nanoparticles for Root Canal Disinfection

    Directory of Open Access Journals (Sweden)

    Ridwan Haseeb

    2016-06-01

    Full Text Available Root canal system disinfection is limited due to anatomical complexities. Better delivery systems of antimicrobial agents are needed to ensure efficient bacteria eradication. The purpose of this study was to design chlorhexidine-containing nanoparticles that could steadily release the drug. The drug chlorhexidine was encapsulated in poly(ethylene glycol–block–poly(l-lactide (PEG–b–PLA to synthesize bilayer nanoparticles. The encapsulation efficiency was determined through thermogravimetric analysis (TGA, and particle characterization was performed through microscopy studies of particle morphology and size. Their antimicrobial effect was assessed over the endodontic pathogen Enterococcus faecalis. The nanoparticles ranged in size from 300–500 nm, which is considered small enough for penetration inside small dentin tubules. The nanoparticles were dispersed in a hydrogel matrix carrier system composed of 1% hydroxyethyl cellulose, and this hydrogel system was observed to have enhanced bacterial inhibition over longer periods of time. Chlorhexidine-containing nanoparticles demonstrate potential as a drug carrier for root canal procedures. Their size and rate of release may allow for sustained inhibition of bacteria in the root canal system.

  3. Substaniation of antimicrobial dressings use in surgery

    Directory of Open Access Journals (Sweden)

    Paliy G.K.

    2014-06-01

    Full Text Available Antimicrobial materials incorporate in their structure modern antiseptics, which have the ability of dischargeng in the environment and provide death of opportunistic microorganisms. The results of the research of antimicrobial qualities of modern dressings, which include decamethoxine, chlorhexidine digluconate, furagin are shown. It was found that strains of Staphylococcus spp., Escherichia spp., Pseudomonas spp. are of high sensitivity to decamethoxin in dressing materials in comparison with textile materials, finished with chlorhexidine digluconate, furagin. The kinetics of decamethoxin release from antimicrobial materials is presented in the article. It was proven, that the release of decametoxin from antimicrobial materials in the environment occurs due to the diffusion and hydrolytic destruction of polymers in aqueous phase, which continues during 15 days.

  4. Third generation cephalosporin resistant Enterobacteriaceae and multidrug resistant gram-negative bacteria causing bacteremia in febrile neutropenia adult cancer patients in Lebanon, broad spectrum antibiotics use as a major risk factor, and correlation with poor prognosis

    Directory of Open Access Journals (Sweden)

    Rima eMoghnieh

    2015-02-01

    Full Text Available Bacteremia remains a major cause of life-threatening complications in patients receiving anticancer chemotherapy. The spectrum and susceptibility profiles of causative microorganisms differ with time and place. Data from Lebanon are scarce. We aim at evaluating the epidemiology of bacteremia in cancer patients in a university hospital in Lebanon, emphasizing antibiotic resistance and risk factors of multi-drug resistant organism (MDRO-associated bacteremia.This is a retrospective study of 75 episodes of bacteremia occurring in febrile neutropenic patients admitted to the hematology-oncology unit at Makassed General Hospital, Lebanon, from October 2009-January 2012.It corresponds to epidemiological data on bacteremia episodes in febrile neutropenic cancer patients including antimicrobial resistance and identification of risk factors associated with third generation cephalosporin resistance (3GCR and MDRO-associated bacteremia. Out of 75 bacteremias, 42.7% were gram-positive (GP, and 57.3% were gram-negative (GN. GP bacteremias were mostly due to methicillin-resistant coagulase negative staphylococci (28% of total bacteremias and 66% of GP bacteremias. Among the GN bacteremias, Escherichia coli (22.7% of total, 39.5% of GN organisms and Klebsiellapneumoniae(13.3% of total, 23.3% of GN organisms were the most important causative agents. GN bacteremia due to 3GC sensitive (3GCS bacteria represented 28% of total bacteremias, while 29% were due to 3GCR bacteria and 9% were due to carbapenem-resistant organisms. There was a significant correlation between bacteremia with MDRO and subsequent intubation, sepsis and mortality. Among potential risk factors, only broad spectrum antibiotic intake >4 days before bacteremia was found to be statistically significant for acquisition of 3GCR bacteria. Using carbapenems or piperacillin/ tazobactam>4 days before bacteremia was significantly associated with the emergence of MDRO (p value<0.05.

  5. ANTIMICROBIAL EFFECT OF A DENTAL VARNISH, INVITRO

    NARCIS (Netherlands)

    PETERSSON, LG; EDWARDSSON, S; ARENDS, J

    1992-01-01

    The effects of a polymer based antimicrobial releasing varnish Cervitec(R) were investigated against different grampositive and gramnegative bacterial strains as well as a yeast using the agar diffusion inhibitory test (ADT-test in vitro). As positive controls a 1 % chlorhexidine gel and 1 % aqueous

  6. 网格蛋白介导型内吞作用与广谱抗病毒药%Clathrin-mediated endocytosis and broad-spectrum antivirals

    Institute of Scientific and Technical Information of China (English)

    周丽; 杨晓虹; 徐利保; 肖军海

    2013-01-01

    Viral disease is a serious threat for human health. Alhough plenty of antiviral agents have been used in clinical treatment, many viruses are resistant to them via virus mutation. And novel harmful viruses emerge in endlessly. So research and development of new antiviral drugs, especially the agents that are of broad-spectrum antiviral activity is particularly important. Clathrin-mediated endocytosis is the most common pathway used by viruses and pathogens for entering host cells. The inhibitors of clathrin-me-diated endocytosis may block the entry of viruses and pathogens, thus prevent viral infection. For the inhibitors do not directly act on the virus itself, it is hard to induce virus mutations which produce drug resistance. Clathrin-mediated endocytosis is the potential target of broad-spectrum antiviral agents in recent years. This review focuses on the mechanism of virus entry through clathrin-mediated endocytosis, the recent advances of clathrin-mediated endocytosis inhibitors and their potential applications in broad-spectrum antiviral therapeutics field.%病毒性疾病对人类的健康造成了巨大的威胁,虽然有很多药物用于临床治疗,但由于病毒的易变异性,对现有的抗病毒药物极易产生耐药性,而新发病毒又层出不穷,因此研发新的抗病毒药物尤其是广谱且不易产生耐药的抗病毒药物对于病毒性疾病的治疗就显得尤为重要.网格蛋白介导型内吞是许多病毒和病原体进入宿主细胞的主要途径,抑制此途径可阻断病毒进入宿主细胞,从而抑制病毒感染,由于其功能和机制与病毒自身无关,不易产生耐药,是近年来广谱抗病毒药物的潜在作用靶标.本文结合国内外最新研究报道,简要综述了病毒依赖网格蛋白介导型内吞入胞的机制,网格蛋白介导型内吞抑制剂的研究现状,及其在广谱抗病毒药物研发中的潜在应用前景.

  7. Nisin and its Antimicrobial Effect in Foods

    OpenAIRE

    Hamparsun Hampikyan; Hilal Colak

    2007-01-01

    Nisin is a bacteriocin which is produced by Lactococcus lactis and takes its place in I. class bacteriocins which are known as lantibiotics. Nisin has antimicrobial and bactericidal activity against a broad spectrum of gram positive bacteria and spores of Clostridium spp. and Bacillus spp. According to toxicity studies nisin is considered not toxic to humans. Its first established used was as a preservative in processed cheese products and since than numerous other applications in various foo...

  8. Chlorhexidine urticaria: A rare occurrence with a common mouthwash

    OpenAIRE

    Sharma Anamika; Chopra Harneet

    2009-01-01

    Chlorhexidine is a widely used antiseptic and disinfectant in medical and nonmedical environments. Compared to its ubiquitous use, allergic contact dermatitis from chlorhexidine has rarely been reported and so its sensitization rate seems to be low. The prevalence of contact urticaria and anaphylaxis due to chlorhexidine remains to be unknown. This case report presents a case of urticaria due to oral use of chlorhexidine. The adverse reaction was confirmed by skin prick test.

  9. Facile synthesis of Fe3O4 nanoparticles decorated on 3D graphene aerogels as broad-spectrum sorbents for water treatment

    Science.gov (United States)

    Li, Yong; Zhang, Ruofang; Tian, Xike; Yang, Chao; Zhou, Zhaoxin

    2016-04-01

    In order to develop efficient and environment benign sorbents for water purification, the macroscopic multifunctional magnetite-reduced graphene oxides aerogels (M-RGOs) with strong interconnected networks were prepared via a one pot solvothermal method of graphene oxide sheets adsorbing iron ions and in situ simultaneous deposition of Fe3O4 nanoparticles in ethylene glycol or triethylene glycol solvents. Such M-RGOs exhibited excellent sorption capacity to different contaminants, including oils, organic solvents, arsenite ions, as well as dyes. In addition, it was demonstrated that the M-RGOs could be used as column packing materials to manufacture column for water purification by filtration. The method proposed was proved to be versatile to induce synergistic assembly of RGO sheets with other functional metal oxides nanoparticles and as a kind of broad-spectrum sorbents for removing different types of contaminants in water purification, simultaneously.

  10. Bio-Inspired Wide-Angle Broad-Spectrum Cylindrical Lens Based on Reflections from Micro-Mirror Array on a Cylindrical Elastomeric Membrane

    Directory of Open Access Journals (Sweden)

    Chi-Chieh Huang

    2014-06-01

    Full Text Available We present a wide-angle, broad-spectrum cylindrical lens based on reflections from an array of three-dimensional, high-aspect-ratio micro-mirrors fabricated on a cylindrical elastomeric substrate, functionally inspired by natural reflecting superposition compound eyes. Our device can perform one-dimensional focusing and beam-shaping comparable to conventional refraction-based cylindrical lenses, while avoiding chromatic aberration. The focal length of our cylindrical lens is 1.035 mm, suitable for micro-optical systems. Moreover, it demonstrates a wide field of view of 152° without distortion, as well as modest spherical aberrations. Our work could be applied to diverse applications including laser diode collimation, barcode scanning, holography, digital projection display, microlens arrays, and optical microscopy.

  11. Antimicrobial peptides and proteins in host-microbe interaction and immediate defense

    OpenAIRE

    Kai-Larsen, Ylva

    2009-01-01

    Antimicrobial peptides and proteins (AMPs) are effector molecules of innate immunity and are capable to kill a broad spectrum of microbes, i.e. bacteria, fungi and viruses. They are widespread in nature and have been found in almost all species of the animal kingdom, as well as in plants. The mammalian repertoire of antimicrobial peptides includes the defensins and the cathelicidins. Furthermore, several of the antimicrobial proteins are members of the S100 family. AMPs are ...

  12. 21 CFR 529.400 - Chlorhexidine tablets and suspension.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Chlorhexidine tablets and suspension. 529.400... Chlorhexidine tablets and suspension. (a) Specification. Each tablet and each 28-milliliter syringe of suspension contain 1 gram of chlorhexidine dihydrochloride.1 1 These conditions are NAS/NRC reviewed...

  13. DETERMINATION OF CHLORHEXIDINE IN SALIVA AND IN AQUEOUS-SOLUTIONS

    NARCIS (Netherlands)

    de Vries, J.; Ruben, J; Arends, J.

    1991-01-01

    A new method is presented for the determination of chlorhexidine in centrifuged saliva and in aqueous solutions by means of fluorescence spectroscopy. The method relies on complex formation between chlorhexidine and eosin. The fluorescence value of the chlorhexidine-eosin system decreases with incre

  14. CaLecRK-S.5, a pepper L-type lectin receptor kinase gene, confers broad-spectrum resistance by activating priming

    Science.gov (United States)

    Woo, Joo Yong; Jeong, Kwang Ju; Kim, Young Jin; Paek, Kyung-Hee

    2016-01-01

    In Arabidopsis, several L-type lectin receptor kinases (LecRKs) have been identified as putative immune receptors. However, to date, there have been few analyses of LecRKs in crop plants. Virus-induced gene silencing of CaLecRK-S.5 verified the role of CaLecRK-S.5 in broad-spectrum resistance. Compared with control plants, CaLecRK-S.5-silenced plants showed reduced hypersensitive response, reactive oxygen species burst, secondary metabolite production, mitogen-activated protein kinase activation, and defense-related gene expression in response to Tobacco mosaic virus pathotype P0 (TMV-P0) infection. Suppression of CaLecRK-S.5 expression significantly enhanced the susceptibility to Pepper mild mottle virus pathotype P1,2,3, Xanthomonas campestris pv. vesicatoria, Phytophthora capsici, as well as TMV-P0. Additionally, β-aminobutyric acid treatment and a systemic acquired resistance assay revealed that CaLecRK-S.5 is involved in priming of plant immunity. Pre-treatment with β-aminobutyric acid before viral infection restored the reduced disease resistance phenotypes shown in CaLecRK-S.5-silenced plants. Systemic acquired resistance was also abolished in CaLecRK-S.5-silenced plants. Finally, RNA sequencing analysis indicated that CaLecRK-S.5 positively regulates plant immunity at the transcriptional level. Altogether, these results suggest that CaLecRK-S.5-mediated broad-spectrum resistance is associated with the regulation of priming. PMID:27647723

  15. Recurrent Methicillin-Resistant Staphylococcus aureus Cutaneous Abscesses and Selection of Reduced Chlorhexidine Susceptibility during Chlorhexidine Use

    OpenAIRE

    Johnson, Ryan C.; Schlett, Carey D.; Crawford, Katrina; Lanier, Jeffrey B.; Merrell, D. Scott; Ellis, Michael W.

    2015-01-01

    We describe the selection of reduced chlorhexidine susceptibility during chlorhexidine use in a patient with two episodes of cutaneous USA300 methicillin-resistant Staphylococcus aureus abscess. The second clinical isolate harbors a novel plasmid that encodes the QacA efflux pump. Greater use of chlorhexidine for disease prevention warrants surveillance for resistance.

  16. Chlorhexidine release and water sorption characteristics of chlorhexidine-incorporated hydrophobic/hydrophilic resins

    OpenAIRE

    Hiraishi, N.; Yiu, C.K.Y.; King, N. M.; Tay, F.R.; Pashley, D.H.

    2008-01-01

    Objectives: The aim of this study was to evaluate chlorhexidine release from unfilled non-solvated methacrylate-based resins of increasing hydrophilicity and to examine relationships among Hoy's solubility parameters, water sorption, solubility and the rate of chlorhexidine release. Methods: Resin discs were prepared from light-cured, experimental resin blends (R1, R2, R3, R4 and R5) containing 0.0, 0.2, 1.0 and 2.0 wt.% chlorhexidine diacetate (CDA). Discs were immersed in distilled water at...

  17. 不同品种香蕉内生菌分离及广谱拮抗菌的筛选%Endophytes Isolation and Broad-spectrum Antagonistic Bacterias Screening from Banana

    Institute of Scientific and Technical Information of China (English)

    王梦颖; 周登博; 井涛; 胡一凤; 高祝芬; 谢晴宜; 张锡炎; 戚春林

    2014-01-01

    In order to determine the main distribution of endophytes and their broad-spectrum antimicrobial activity, endophytes were obtained from healthy and diseased tissues of two disease-resistant and one disease susceptible banana cultivars. Endophytes were separated from roots, corms, pseudostems, leaves and store in the ultra-low on Luria-Bertani(LB), Yeast Extract with supplements(YE), and Potato Dextrose Agar(PDA)strain store medium. Then screened broad-spectrum antagonistic bacteria which against Fusarium oxysporum f. sp. Cubense, Curvularia lunata, Curvularia fallax, Corynespora cassiicola(Berk&Curt)Wei, Alternaria musae, Deightoniella troulosa, Colletotrichum musae, Pestalogiopsis sp., Btoryosphaeria dothidea. Taxonomy identification of 041, 04-1, 19-1, 03A-1 was conducted by evaluating morphologic characteristics and 16S rDNA gene sequences for phylogenetic analysis. After purification, total of 438 endophytes were obtained. The total of isolates showed that we obtained 240 strains bacteria, followed by 142 strains actinomycetes, and 56 strains fungi. The richest number of endophytes that isolated from diseased NanTian banana cultivars(128). Ten actinomyces and two bacterias were determined to possess antibiotic activity against Ten banana pathogens. Isolates 041 was the most effective and had 28.13±1.89 mm width of inhibition zone. Isolated 041, 04-1, 19-1, 034-1 were identified as Streptomyces misionensis.%旨在探究抗病品种与易感品种香蕉的健康株和病株内生菌与其中广谱拮抗菌的主要分布规律,并对广谱拮抗菌进行拮抗活性的测定。以样品根、球茎、假茎、叶为材料分离培养内生菌,在实验室条件下,筛选对供试的10种香蕉致病菌均有良好拮抗活性的菌株并测定它们的拮抗活性,对活性最强的菌株进行形态学、16S rDNA序列同源性分析。结果显示,分离得到内生菌438株,其中细菌240株,放线菌142株,真菌56株。抗病品种南天

  18. Evaluation of the antimicrobial and physical properties of an orthodontic photo-activated adhesive modified with an antiplaque agent: An in vitro study

    Directory of Open Access Journals (Sweden)

    Chanjyot Singh

    2013-01-01

    Results: The findings indicated that (1 addition of chlorhexidine to the orthodontic composite resin enhanced its antimicrobial properties, (2 there was no significant difference between the bond strengths of the control and the experimental resins tested after 24 h and 25 days and (3 maximum release of chlorhexidine from the modified resin was much higher than the minimum inhibitory concentration level.

  19. Oral chlorhexidine and microbial contamination during endoscopy

    DEFF Research Database (Denmark)

    Donatsky, Anders Meller; Holzknecht, Barbara Juliane; Arpi, Magnus;

    2013-01-01

    BACKGROUND: One of the biggest concerns associated with transgastric surgery is contamination and risk of intra-abdominal infection with microbes introduced from the access route. The purpose of this study was to evaluate the effect of oral decontamination with chlorhexidine on microbial contamin......BACKGROUND: One of the biggest concerns associated with transgastric surgery is contamination and risk of intra-abdominal infection with microbes introduced from the access route. The purpose of this study was to evaluate the effect of oral decontamination with chlorhexidine on microbial...

  20. Preclinical Bioassay of a Polypropylene Mesh for Hernia Repair Pretreated with Antibacterial Solutions of Chlorhexidine and Allicin: An In Vivo Study.

    Directory of Open Access Journals (Sweden)

    Bárbara Pérez-Köhler

    Full Text Available Prosthetic mesh infection constitutes one of the major complications following hernia repair. Antimicrobial, non-antibiotic biomaterials have the potential to reduce bacterial adhesion to the mesh surface and adjacent tissues while avoiding the development of novel antibiotic resistance. This study assesses the efficacy of presoaking reticular polypropylene meshes in chlorhexidine or a chlorhexidine and allicin combination (a natural antibacterial agent for preventing bacterial infection in a short-time hernia-repair rabbit model.Partial hernia defects (5 x 2 cm were created on the lateral right side of the abdominal wall of New Zealand White rabbits (n = 21. The defects were inoculated with 0.5 mL of a 106 CFU/mL Staphylococcus aureus ATCC25923 strain and repaired with a DualMesh Plus antimicrobial mesh or a Surgipro mesh presoaked in either chlorhexidine (0.05% or allicin-chlorhexidine (900 μg/mL-0.05%. Fourteen days post-implant, mesh contraction was measured and tissue specimens were harvested to evaluate bacterial adhesion to the implant surface (via sonication, S. aureus immunolabeling, host-tissue incorporation (via staining, scanning electron microscopy and macrophage response (via RAM-11 immunolabeling.The polypropylene mesh showed improved tissue integration relative to the DualMesh Plus. Both the DualMesh Plus and the chlorhexidine-soaked polypropylene meshes exhibited high bacterial clearance, with the latter material showing lower bacterial yields. The implants from the allicin-chlorhexidine group displayed a neoformed tissue containing differently sized abscesses and living bacteria, as well as a diminished macrophage response. The allicin-chlorhexidine coated implants exhibited the highest contraction.The presoaking of reticular polypropylene materials with a low concentration of chlorhexidine provides the mesh with antibacterial activity without disrupting tissue integration. Due to the similarities found with the antimicrobial

  1. Long-term and controlled release of chlorhexidine-copper(II) from organically modified montmorillonite (OMMT) nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yue [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097 (China); Jiangsu Engineering Research Center for Biomedical Function Materials, Nanjing Normal University, Nanjing 210097 (China); Zhou, Ninglin, E-mail: zhouninglin@njnu.edu.cn [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097 (China); Jiangsu Engineering Research Center for Biomedical Function Materials, Nanjing Normal University, Nanjing 210097 (China); Jiangsu Technological Research Center for Interfacial Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Li, Wenhao; Gu, Hao; Fan, Yunting [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097 (China); Jiangsu Engineering Research Center for Biomedical Function Materials, Nanjing Normal University, Nanjing 210097 (China); Yuan, Jiang, E-mail: bioalchem@yahoo.com [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097 (China); Jiangsu Engineering Research Center for Biomedical Function Materials, Nanjing Normal University, Nanjing 210097 (China); Jiangsu Technological Research Center for Interfacial Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China)

    2013-03-01

    Drug/metal ion complexes exhibit improved antimicrobial activity and intercalating the above complexes into the interlayer of clay endows a long-term and controlled-release behavior. In this study, chlorhexidine was first complexed with copper (II) ion and then intercalated into the interlayer of MMT to form chlorhexidine-copper (II)/montmorillonite (CHX-Cu/MMT) nanocomposites. The nanocomposites were characterized with Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). A nearly lateral-monolayer arrangement of CHX-Cu was supposed for the intercalation. Release kinetics indicated that the release process satisfied a pseudo-second-order mode. The antibacterial results showed that the CHX-Cu/MMT composites had long-term and controlled-release behavior. - Graphical abstract: The antibacterial agent of chlorhexidine was first complexed with copper(II) chloride and then intercalated into the interlayer of MMT to form nanocomposites. The CHX-Cu/MMT composites exhibited long-term antibacterial activity and controlled release behaviors. Highlights: Black-Right-Pointing-Pointer Chlorhexidine-copper (II)/montmorillonite (CHX-Cu/MMT) complex exhibits improved antimicrobial activity. Black-Right-Pointing-Pointer Intercalating chlorhexidine-copper (II) complex into the interlayer of clay endows a long-term and controlled-release. Black-Right-Pointing-Pointer Release kinetics indicated that the release process satisfied a pseudo-second-order mode. Black-Right-Pointing-Pointer A nearly lateral-monolayer arrangement of CHX-Cu was supposed for the intercalation.

  2. Varespladib (LY315920 Appears to Be a Potent, Broad-Spectrum, Inhibitor of Snake Venom Phospholipase A2 and a Possible Pre-Referral Treatment for Envenomation

    Directory of Open Access Journals (Sweden)

    Matthew Lewin

    2016-08-01

    Full Text Available Snakebite remains a neglected medical problem of the developing world with up to 125,000 deaths each year despite more than a century of calls to improve snakebite prevention and care. An estimated 75% of fatalities from snakebite occur outside the hospital setting. Because phospholipase A2 (PLA2 activity is an important component of venom toxicity, we sought candidate PLA2 inhibitors by directly testing drugs. Surprisingly, varespladib and its orally bioavailable prodrug, methyl-varespladib showed high-level secretory PLA2 (sPLA2 inhibition at nanomolar and picomolar concentrations against 28 medically important snake venoms from six continents. In vivo proof-of-concept studies with varespladib had striking survival benefit against lethal doses of Micrurus fulvius and Vipera berus venom, and suppressed venom-induced sPLA2 activity in rats challenged with 100% lethal doses of M. fulvius venom. Rapid development and deployment of a broad-spectrum PLA2 inhibitor alone or in combination with other small molecule inhibitors of snake toxins (e.g., metalloproteases could fill the critical therapeutic gap spanning pre-referral and hospital setting. Lower barriers for clinical testing of safety tested, repurposed small molecule therapeutics are a potentially economical and effective path forward to fill the pre-referral gap in the setting of snakebite.

  3. Tallow amphopolycarboxyglycinate-stabilized silver nanoparticles: new frontiers in development of plant protection products with a broad spectrum of action against phytopathogens

    Science.gov (United States)

    Krutyakov, Yurii A.; Kudrinskiy, Alexey A.; Zherebin, Pavel M.; Yapryntsev, Alexey D.; Pobedinskaya, Marina A.; Elansky, Sergey N.; Denisov, Albert N.; Mikhaylov, Dmitry M.; Lisichkin, Georgii V.

    2016-07-01

    Sustainable agriculture calls for minimal use of agrochemicals in order to protect the environment. It has caused an increase in the rate of nanoparticles use, in particular silver nanoparticles (AgNPs) due to their safety for mammals, unique biological activity and a broad spectrum of action against fungal and bacterial pathogens. Until now the use of AgNPs dispersions in the agricultural sector has been essentially limited due to many factors decreased their stability (mixing with other pesticides, presence of electrolytes). We present a versatile synthesis of polyampholyte surfactant (tallow amphopolycarboxyglycinate) stabilized AgNPs. We took a close look at unique aggregation behavior (via dynamic light scattering and UV-vis spectroscopy) and biocidal activity of obtained silver colloids. AgNPs are characterized by exclusively high aggregative stability in the presence of coagulating agents NaNO3 and NaSO4 (up to 1 M), during drying/redispergation, and frost/defrost cycles. The dispersion of AgNPs shows high biocidal activity (EC50 is ten times lower than commercial species ones) with respect to Phytophthora infestans and phytopathogenic fungi. This points to the possibility of successful application of silver preparations within agriculture with the goal of partial reduction of the use of toxic and expensive synthetic antibiotics and pesticides.

  4. Albendazole, a broad-spectrum anthelmintic, in the treatment of intestinal nematode and cestode infection: a multicenter study in 480 patients.

    Science.gov (United States)

    Jagota, S C

    1986-01-01

    The anthelmintic activity of and patient tolerance to albendazole, a broad-spectrum anthelmintic, were studied in a multicenter trial involving 480 patients ranging in age from 2 to 60 years. The patients had single or mixed infections caused by pinworms, roundworms, hookworms, whipworms, threadworms, or tapeworms. The stools were examined by the direct method, and ova were counted by means of the Kato-Katz technique. A Graham-Scotch test was also done in patients infected with Enterobius vermicularis. Most patients received a single 400-mg dose of albendazole; adults were given two tablets, and children were given a 2% suspension. All patients with Hymenolepis nana and about half of those with Taenia infections were treated for three successive days. Patients were carefully evaluated before and after treatment to assess the efficacy and safety of the drug. After a single dose of albendazole, the cure rate was 95.3% in ascariasis, 92.2% in ancylostomiasis, 90.5% in trichuriasis, 64.9% in taeniasis, and 100% in enterobiasis. Among patients receiving 400 mg of albendazole for three days, the cure rate was 63.4% in hymenolepiasis and 86.1% in taeniasis. The drug was well tolerated, and no significant side effects were reported. PMID:3516398

  5. Varespladib (LY315920) Appears to Be a Potent, Broad-Spectrum, Inhibitor of Snake Venom Phospholipase A2 and a Possible Pre-Referral Treatment for Envenomation.

    Science.gov (United States)

    Lewin, Matthew; Samuel, Stephen; Merkel, Janie; Bickler, Philip

    2016-01-01

    Snakebite remains a neglected medical problem of the developing world with up to 125,000 deaths each year despite more than a century of calls to improve snakebite prevention and care. An estimated 75% of fatalities from snakebite occur outside the hospital setting. Because phospholipase A2 (PLA2) activity is an important component of venom toxicity, we sought candidate PLA2 inhibitors by directly testing drugs. Surprisingly, varespladib and its orally bioavailable prodrug, methyl-varespladib showed high-level secretory PLA2 (sPLA2) inhibition at nanomolar and picomolar concentrations against 28 medically important snake venoms from six continents. In vivo proof-of-concept studies with varespladib had striking survival benefit against lethal doses of Micrurus fulvius and Vipera berus venom, and suppressed venom-induced sPLA2 activity in rats challenged with 100% lethal doses of M. fulvius venom. Rapid development and deployment of a broad-spectrum PLA2 inhibitor alone or in combination with other small molecule inhibitors of snake toxins (e.g., metalloproteases) could fill the critical therapeutic gap spanning pre-referral and hospital setting. Lower barriers for clinical testing of safety tested, repurposed small molecule therapeutics are a potentially economical and effective path forward to fill the pre-referral gap in the setting of snakebite. PMID:27571102

  6. Varespladib (LY315920) Appears to Be a Potent, Broad-Spectrum, Inhibitor of Snake Venom Phospholipase A2 and a Possible Pre-Referral Treatment for Envenomation

    Science.gov (United States)

    Lewin, Matthew; Samuel, Stephen; Merkel, Janie; Bickler, Philip

    2016-01-01

    Snakebite remains a neglected medical problem of the developing world with up to 125,000 deaths each year despite more than a century of calls to improve snakebite prevention and care. An estimated 75% of fatalities from snakebite occur outside the hospital setting. Because phospholipase A2 (PLA2) activity is an important component of venom toxicity, we sought candidate PLA2 inhibitors by directly testing drugs. Surprisingly, varespladib and its orally bioavailable prodrug, methyl-varespladib showed high-level secretory PLA2 (sPLA2) inhibition at nanomolar and picomolar concentrations against 28 medically important snake venoms from six continents. In vivo proof-of-concept studies with varespladib had striking survival benefit against lethal doses of Micrurus fulvius and Vipera berus venom, and suppressed venom-induced sPLA2 activity in rats challenged with 100% lethal doses of M. fulvius venom. Rapid development and deployment of a broad-spectrum PLA2 inhibitor alone or in combination with other small molecule inhibitors of snake toxins (e.g., metalloproteases) could fill the critical therapeutic gap spanning pre-referral and hospital setting. Lower barriers for clinical testing of safety tested, repurposed small molecule therapeutics are a potentially economical and effective path forward to fill the pre-referral gap in the setting of snakebite. PMID:27571102

  7. Efficacy of oral E1210, a new broad-spectrum antifungal with a novel mechanism of action, in murine models of candidiasis, aspergillosis, and fusariosis.

    Science.gov (United States)

    Hata, Katsura; Horii, Takaaki; Miyazaki, Mamiko; Watanabe, Nao-Aki; Okubo, Miyuki; Sonoda, Jiro; Nakamoto, Kazutaka; Tanaka, Keigo; Shirotori, Syuji; Murai, Norio; Inoue, Satoshi; Matsukura, Masayuki; Abe, Shinya; Yoshimatsu, Kentaro; Asada, Makoto

    2011-10-01

    E1210 is a first-in-class, broad-spectrum antifungal with a novel mechanism of action-inhibition of fungal glycosylphosphatidylinositol biosynthesis. In this study, the efficacies of E1210 and reference antifungals were evaluated in murine models of oropharyngeal and disseminated candidiasis, pulmonary aspergillosis, and disseminated fusariosis. Oral E1210 demonstrated dose-dependent efficacy in infections caused by Candida species, Aspergillus spp., and Fusarium solani. In the treatment of oropharyngeal candidiasis, E1210 and fluconazole each caused a significantly greater reduction in the number of oral CFU than the control treatment (P candidiasis model, mice treated with E1210, fluconazole, caspofungin, or liposomal amphotericin B showed significantly higher survival rates than the control mice (P candidiasis caused by azole-resistant Candida albicans or Candida tropicalis. A 24-h delay in treatment onset minimally affected the efficacy outcome of E1210 in the treatment of disseminated candidiasis. In the Aspergillus flavus pulmonary aspergillosis model, mice treated with E1210, voriconazole, or caspofungin showed significantly higher survival rates than the control mice (P candidiasis, pulmonary aspergillosis, and disseminated fusariosis. These data suggest that further studies to determine E1210's potential for the treatment of disseminated fungal infections are indicated.

  8. Tallow amphopolycarboxyglycinate-stabilized silver nanoparticles: new frontiers in development of plant protection products with a broad spectrum of action against phytopathogens

    Science.gov (United States)

    Krutyakov, Yurii A.; Kudrinskiy, Alexey A.; Zherebin, Pavel M.; Yapryntsev, Alexey D.; Pobedinskaya, Marina A.; Elansky, Sergey N.; Denisov, Albert N.; Mikhaylov, Dmitry M.; Lisichkin, Georgii V.

    2016-07-01

    Sustainable agriculture calls for minimal use of agrochemicals in order to protect the environment. It has caused an increase in the rate of nanoparticles use, in particular silver nanoparticles (AgNPs) due to their safety for mammals, unique biological activity and a broad spectrum of action against fungal and bacterial pathogens. Until now the use of AgNPs dispersions in the agricultural sector has been essentially limited due to many factors decreased their stability (mixing with other pesticides, presence of electrolytes). We present a versatile synthesis of polyampholyte surfactant (tallow amphopolycarboxyglycinate) stabilized AgNPs. We took a close look at unique aggregation behavior (via dynamic light scattering and UV–vis spectroscopy) and biocidal activity of obtained silver colloids. AgNPs are characterized by exclusively high aggregative stability in the presence of coagulating agents NaNO3 and NaSO4 (up to 1 M), during drying/redispergation, and frost/defrost cycles. The dispersion of AgNPs shows high biocidal activity (EC50 is ten times lower than commercial species ones) with respect to Phytophthora infestans and phytopathogenic fungi. This points to the possibility of successful application of silver preparations within agriculture with the goal of partial reduction of the use of toxic and expensive synthetic antibiotics and pesticides.

  9. Protease-sensitive conformers in broad spectrum of distinct PrPSc structures in sporadic Creutzfeldt-Jakob disease are indicator of progression rate.

    Directory of Open Access Journals (Sweden)

    Chae Kim

    2011-09-01

    Full Text Available The origin, range, and structure of prions causing the most common human prion disease, sporadic Creutzfeldt-Jakob disease (sCJD, are largely unknown. To investigate the molecular mechanism responsible for the broad phenotypic variability of sCJD, we analyzed the conformational characteristics of protease-sensitive and protease-resistant fractions of the pathogenic prion protein (PrP(Sc using novel conformational methods derived from a conformation-dependent immunoassay (CDI. In 46 brains of patients homozygous for polymorphisms in the PRNP gene and exhibiting either Type 1 or Type 2 western blot pattern of the PrP(Sc, we identified an extensive array of PrP(Sc structures that differ in protease sensitivity, display of critical domains, and conformational stability. Surprisingly, in sCJD cases homozygous for methionine or valine at codon 129 of the PRNP gene, the concentration and stability of protease-sensitive conformers of PrP(Sc correlated with progression rate of the disease. These data indicate that sCJD brains exhibit a wide spectrum of PrP(Sc structural states, and accordingly argue for a broad spectrum of prion strains coding for different phenotypes. The link between disease duration, levels, and stability of protease-sensitive conformers of PrP(Sc suggests that these conformers play an important role in the pathogenesis of sCJD.

  10. Characterization and Genetic Analysis of a Novel Rice Spotted-leaf Mutant HM47 with Broad-spectrum Resistance to Xanthomonas oryzae pv.oryzae(F)

    Institute of Scientific and Technical Information of China (English)

    Bao-Hua Feng; Yang Yang; Yong-Feng Shi; Hai-Chao Shen; Hui-Mei Wang; Qi-Na Huang; Xia Xu

    2013-01-01

    A stable inherited rice spotted-leaf mutant HM47 derived from an EMS-induced IR64 mutant bank was identified.The mutant expressed hypersensitive response (HR)-like symptoms throughout its whole life from the first leaf to the flag leaf,without pathogen invasion.Initiation of the lesions was induced by light under natural summer field conditions.Expression of pathogenesis-related genes including PAL,PO-C1,POX22.3 and PBZ1 was enhanced significantly in association with cell death and accumulation of H2O2 at and around the site of lesions in the mutant in contrast to that in the wild-type (WT).Disease reaction to Xanthomonas oryzae pv.oryzae from the Philippines and China showed that HM47 is a broad-spectrum disease-resistant mutant with enhanced resistance to multiple races of bacterial blight pathogens tested.An F2 progeny test showed that bacterial blight resistance to race HB-17 was cosegregated with the expression of lesions.Genetic analysis indicated that the spotted-leaf trait was controlled by a single recessive gene,tentatively named splHM47,flanked by two insertion/deletion markers in a region of approximately 74 kb on the long arm of chromosome 4.Ten open reading frames are predicted,and all of them are expressed proteins.Isolation and validation of the putative genes are currently underway.

  11. Prevention of biofilm colonization by Gram-negative bacteria on minocycline-rifampin-impregnated catheters sequentially coated with chlorhexidine.

    Science.gov (United States)

    Jamal, Mohamed A; Rosenblatt, Joel S; Hachem, Ray Y; Ying, Jiang; Pravinkumar, Egbert; Nates, Joseph L; Chaftari, Anne-Marie P; Raad, Issam I

    2014-01-01

    Resistant Gram-negative bacteria are increasing central-line-associated bloodstream infection threats. To better combat this, chlorhexidine (CHX) was added to minocycline-rifampin (M/R) catheters. The in vitro antimicrobial activity of CHX-M/R catheters against multidrug resistant, Gram-negative Acinetobacter baumannii, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia was tested. M/R and CHX-silver sulfadiazine (CHX/SS) catheters were used as comparators. The novel CHX-M/R catheters were significantly more effective (P catheters in preventing biofilm colonization and showed better antimicrobial durability.

  12. Influence of application of chlorhexidine gel and curcumin gel as an adjunct to scaling and root planing: A interventional study

    Science.gov (United States)

    Hugar, Shweta S.; Patil, Suvarna; Metgud, Renuka; Nanjwade, Basavraj; Hugar, Shivayogi M.

    2016-01-01

    Background: Currently, the most common therapy for periodontal diseases consists of professional scaling and root planing (SRP). However, it was found to be of limited efficacy especially in areas which are inaccessible to periodontal instrumentation. Therefore, treatment strategies using antimicrobials in conjunction with conventional therapy have evolved. Thus, the study was undertaken with an. Aim: To evaluate the efficacy of application of chlorhexidine gel and curcumin gel as an adjunct to SRP. Materials and Methods: The study was conducted on thirty chronic periodontitis patients who were divided into two groups as control and experimental groups using a split-mouth design. After SRP chlorhexidine gel was applied in control and curcumin gel in experimental groups. The plaque index, gingival index, sulcus bleeding index, probing pocket depth were recorded at baseline and subsequently after 1 month and 45 days. Results: The results revealed that both chlorhexidine gel and curcumin gel have an effect on mild to moderate periodontal pockets in chronic periodontitis patients, but greater reduction was observed in the experimental group than the control group. Conclusion: It can be concluded that both control and experimental gel can be used as an adjunct to SRP, but the curcumin gel was more effective than the chlorhexidine gel in the treatment of mild to moderate periodontal pockets with a significant reduction in the indice scores when compared to the baseline values. PMID:27433065

  13. Antimicrobial activity of Eucalyptus globulus oil, xylitol and papain: a pilot study

    Directory of Open Access Journals (Sweden)

    Valéria de Siqueira Mota

    2015-04-01

    Full Text Available OBJECTIVE To evaluate the in vitro antimicrobial activity of the Eucalyptus globulus essential oil, and of the xylitol and papain substances against the following microorganisms: Pseudomonas aeruginosa; Samonella sp.; Staphylococus aureus; Proteus vulgaris; Escherichia coli and Candida albicans. METHOD The in vitro antimicrobial evaluation was used by means of the agar diffusion test and evaluation of the inhibition zone diameter of the tested substances. Chlorhexidine 0.5% was used as control. RESULTS The Eucalyptus globulus oil showed higher inhibition than chlorhexidine when applied to Staphylococcus aureus, and equal inhibition when applied to the following microorganisms: Escherichia coli, Proteus vulgaris and Candida albicans. Papain 10% showed lower antimicrobial effect than chlorhexidine in relation to Candida albicans. Xylitol showed no inhibition of the tested microorganisms. CONCLUSION The Eucalyptus globulus oil has antimicrobial activity against different microorganisms and appears to be a viable alternative as germicidal agent hence, further investigation is recommended.

  14. [Estimation of antimicrobial means action efficacy in children oral cavities by pH-test].

    Science.gov (United States)

    Guliamov, S S

    2009-01-01

    Possibility of mixed saliva pH determination in the efficacy of antimicrobial mean action was assessed using fluctuations in hydrogen index (pH following consumption of sweets in teenagers according to Stephan curve). Antimicrobial activity of chlorhexidine-containing preparation Eludrile and Elgidium-tooth paste, as well as furacillin solution in oral cavities of teenagers was estimated. PMID:19365352

  15. Chlorhexidine gel associated with papain in pulp tissue dissolution

    OpenAIRE

    Couto De Oliveira, Gabriel; Ferraz, Caio Souza; Andrade Júnior, Carlos Vieira; PITHON, Matheus Melo

    2013-01-01

    Objectives This study aimed to evaluate the capacity of 2% chlorhexidine gel associated with 8% papain gel in comparison with 5.25% sodium hypochlorite in bovine pulp tissue dissolution. Materials and Methods Ninety bovine pulps of standardized sizes were used and fragmented into 5-mm sizes. The fragments were removed from the root middle third region. They were divided into 6 experimental groups (n = 15), 1) 8% papain; 2) 2% chlorhexidine; 3) 2% chlorhexidine associated with 8% papain; 4) 0....

  16. Experimental evaluation of chlorhexidine gluconate for ocular antisepsis.

    OpenAIRE

    Hamill, M B; Osato, M S; Wilhelmus, K R

    1984-01-01

    Chlorhexidine gluconate is a bisguanide germicide currently available with 70% isopropanol (Hibistat, Hibitane) or a detergent (Hibiclens, Hibiscrub) for preoperative skin preparation. As these solvents are toxic to the cornea, we investigated the safety and efficacy of aqueous chlorhexidine solutions for ophthalmic use. Chlorhexidine in Tris-glycine buffer was evaluated for retardation of epithelial regeneration after experimental corneal abrasion in rabbits. Irrigant concentrations of 2.0 a...

  17. Chlorhexidine, A Medicine for all the Oral Diseases

    OpenAIRE

    Radhika Gupta; Vidya Chandavarkar; Sushama R Galgali; Mithilesh Mishra

    2012-01-01

    Chlorhexidine is a bisbiguanide antiseptic. It is active against both Gram-positive and Gram-negative strains as well as fungi. It has bacteriostatic and bactericidal actions. Chlorhexidine has excellent antiplaque activity and unique property of substantivity. So it has got wide applications starting from maintaining oral hygiene pre surgically to post operative and also in physically and mentally handicapped patients. Chlorhexidine is now routinely used by clinicians when they treat patient...

  18. Natural herbicide resistance (HR) to broad-spectrum herbicide, glyphosate among traditional and inbred-cultivated rice (Oryza sativa L.) varieties in Sri Lanka.

    Science.gov (United States)

    Weerakoon, S R; Somaratne, S; Wijeratne, R G D; Ekanyaka, E M S I

    2013-08-15

    Weeds along with insect pests and plant diseases are sources of biotic stress in crop systems. Weeds are responsible for serious problems in rice worldwide affecting growth and causing a considerable reduction in quality and quantity in yield. High concentrations of pre-emergent-broad-spectrum systemic herbicide, Glyphosate is prevalently applied to control rice weeds which intern causes severe damages to cultivated rice varieties, susceptible to Glyphosate. However, there may be rice varieties with natural Herbicide Resistance (HR) which are so far, has not been evaluated. In this study Six traditional and eighteen developed-cultivated rice varieties (Bg, Bw, At and Ld series developed by Rice Research Development Institute, Sri Lanka) were used to screen their natural HR. RCBD with five replicates and three blocks in each treatment-combination was used as the experimental design. As observations, time taken-to seed germination, time taken to flowering; plant height and number of leaves at 12-weeks after sawing, leaf-length, breadth, panicle-length, number of seeds/panicle of resistant plants and controls were recorded. Plants with > or = 40% resistance were considered as resistant to Glyphosate. Ten inbred-cultivated rice varieties (Bg250, Bg94-1, Bg304, Bg359, Bg406, Bg379-2, Bg366, Bg300, Bw364, At362) and three traditional rice varieties ("Kalu Heenati", "Sudu Heenati", "Pachchaperumal") were naturally resistant to 0.25 g L(-1) Glyphosate concentration and when increased the concentration (0.5 g L(-1)) resistance was reduced. This study showed the usefulness of modern statistical method, classification and regression tree analysis (CART) in exploring and visualizing the patterns reflected by a large number of rice varieties (larger experimental database) on herbicide resistance in future.

  19. Co-administration of the broad-spectrum antiviral, brincidofovir (CMX001), with smallpox vaccine does not compromise vaccine protection in mice challenged with ectromelia virus.

    Science.gov (United States)

    Parker, Scott; Crump, Ryan; Foster, Scott; Hartzler, Hollyce; Hembrador, Ed; Lanier, E Randall; Painter, George; Schriewer, Jill; Trost, Lawrence C; Buller, R Mark

    2014-11-01

    Natural orthopoxvirus outbreaks such as vaccinia, cowpox, cattlepox and buffalopox continue to cause morbidity in the human population. Monkeypox virus remains a significant agent of morbidity and mortality in Africa. Furthermore, monkeypox virus's broad host-range and expanding environs make it of particular concern as an emerging human pathogen. Monkeypox virus and variola virus (the etiological agent of smallpox) are both potential agents of bioterrorism. The first line response to orthopoxvirus disease is through vaccination with first-generation and second-generation vaccines, such as Dryvax and ACAM2000. Although these vaccines provide excellent protection, their widespread use is impeded by the high level of adverse events associated with vaccination using live, attenuated virus. It is possible that vaccines could be used in combination with antiviral drugs to reduce the incidence and severity of vaccine-associated adverse events, or as a preventive in individuals with uncertain exposure status or contraindication to vaccination. We have used the intranasal mousepox (ectromelia) model to evaluate the efficacy of vaccination with Dryvax or ACAM2000 in conjunction with treatment using the broad spectrum antiviral, brincidofovir (BCV, CMX001). We found that co-treatment with BCV reduced the severity of vaccination-associated lesion development. Although the immune response to vaccination was quantifiably attenuated, vaccination combined with BCV treatment did not alter the development of full protective immunity, even when administered two days following ectromelia challenge. Studies with a non-replicating vaccine, ACAM3000 (MVA), confirmed that BCV's mechanism of attenuating the immune response following vaccination with live virus was, as expected, by limiting viral replication and not through inhibition of the immune system. These studies suggest that, in the setting of post-exposure prophylaxis, co-administration of BCV with vaccination should be considered

  20. Induction of a peptide with activity against a broad spectrum of pathogens in the Aedes aegypti salivary gland, following Infection with Dengue Virus.

    Directory of Open Access Journals (Sweden)

    Natthanej Luplertlop

    Full Text Available The ultimate stage of the transmission of Dengue Virus (DENV to man is strongly dependent on crosstalk between the virus and the immune system of its vector Aedes aegypti (Ae. aegypti. Infection of the mosquito's salivary glands by DENV is the final step prior to viral transmission. Therefore, in the present study, we have determined the modulatory effects of DENV infection on the immune response in this organ by carrying out a functional genomic analysis of uninfected salivary glands and salivary glands of female Ae. aegypti mosquitoes infected with DENV. We have shown that DENV infection of salivary glands strongly up-regulates the expression of genes that encode proteins involved in the vector's innate immune response, including the immune deficiency (IMD and Toll signalling pathways, and that it induces the expression of the gene encoding a putative anti-bacterial, cecropin-like, peptide (AAEL000598. Both the chemically synthesized non-cleaved, signal peptide-containing gene product of AAEL000598, and the cleaved, mature form, were found to exert, in addition to antibacterial activity, anti-DENV and anti-Chikungunya viral activity. However, in contrast to the mature form, the immature cecropin peptide was far more effective against Chikungunya virus (CHIKV and, furthermore, had strong anti-parasite activity as shown by its ability to kill Leishmania spp. Results from circular dichroism analysis showed that the immature form more readily adopts a helical conformation which would help it to cause membrane permeabilization, thus permitting its transfer across hydrophobic cell surfaces, which may explain the difference in the anti-pathogenic activity between the two forms. The present study underscores not only the importance of DENV-induced cecropin in the innate immune response of Ae. aegypti, but also emphasizes the broad-spectrum anti-pathogenic activity of the immature, signal peptide-containing form of this peptide.

  1. Characterization of Disopyramide derivative ADD424042 as a non-cardiotoxic neuronal sodium channel blocker with broad-spectrum anticonvulsant activity in rodent seizure models.

    Science.gov (United States)

    Król, Marek; Ufnal, Marcin; Szulczyk, Bartłomiej; Podsadni, Piotr; Drapała, Adrian; Turło, Jadwiga; Dawidowski, Maciej

    2016-01-01

    It was reported that antiarrhythmic drugs (AADs) can be useful in controlling refractory seizures in humans or in enhancing the action of antiepileptic drugs (AEDs) in animal models. Disopyramide phosphate (DISO) is an AAD that blocks sodium channels in cardiac myocytes. We evaluated a DISO derivative, 2-(2-chlorophenyl)-2-(pyridin-2-yl)acetamide (ADD424042) for its anticonvulsant activity in a battery of rodent models of epileptic seizures. The compound displayed a broad spectrum of activity in the 'classical' models as well as in the models of pharmacoresistant seizures. Furthermore, ADD424042 showed good therapeutic indices between the anticonvulsant activity and the motor impairment. On the contrary, no anticonvulsant effects but severe lethality were observed in the primary anticonvulsant testing of the parent DISO. By performing the whole-cell voltage-clamp experiments in dispersed cortical neurons we demonstrated that ADD424042 decreased the maximal amplitude of voltage-gated sodium channels with an IC50 value in nM range. Moreover, the compound enhanced use-dependent block and decreased excitability in pyramidal neurons in the current-clamp experiments in cortical slices. Importantly, we found that ADD424042 possessed either no, or very small cardiotoxic effect. In contrast to DISO, ADD424042 did not produce any apparent changes in electrocardiogram (ECG) and arterial blood pressure recordings. ADD424042 had no effect on QT and corrected QT intervals, at a dose which was 15 times higher than ED50 for the anticonvulsant effect in the MES model. Taken together, these data suggest that ADD424042 has the potential to become a lead structure for novel broadly acting AEDs with wide margin of cardiac safety.

  2. Broad-spectrum drug screening of meconium by liquid chromatography with tandem mass spectrometry and time-of-flight mass spectrometry.

    Science.gov (United States)

    Ristimaa, Johanna; Gergov, Merja; Pelander, Anna; Halmesmäki, Erja; Ojanperä, Ilkka

    2010-09-01

    Analysis of the major drugs of abuse in meconium has been established in clinical practice for detecting fetal exposure to illicit drugs, particularly for the ready availability of the sample and ease of collection from diapers, compared with neonatal hair and urine. Very little is known about the occurrence and detection possibilities of therapeutic and licit drugs in meconium. Meconium specimens (n = 209) were collected in delivery hospitals, from infants of mothers who were suspected to be drug abusers. A targeted analysis method by liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS) was developed for abused drugs: amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, morphine, codeine, 6-monoacetylmorphine, oxycodone, methadone, tramadol, buprenorphine, and norbuprenorphine. A separate LC-MS/MS method was developed for 11-nor-∆(9)-tetrahydrocannabinol-9-carboxylic acid. A screening method based on LC coupled to time-of-flight MS was applied to a broad spectrum of drugs. As a result, a total of 77 different compounds were found. The main drug findings in meconium were as follows: local anesthetics 82.5% (n = 172), nicotine or its metabolites 61.5% (n = 129), opioids 48.5% (n = 101), stimulants 21.0% (n = 44), hypnotics and sedatives 19.0% (n = 40), antidepressants 18.0% (n = 38), antipsychotics 5.5% (n = 11), and cannabis 3.0% (n = 5). By revealing drugs and metabolites beyond the ordinary scope, the present procedure helps the pediatrician in cases where maternal denial is strong but the infant seems to suffer from typical drug-withdrawal symptoms. Intrapartum drug administration cannot be differentiated from gestational drug use by meconium analysis, which affects the interpretation of oxycodone, tramadol, fentanyl, pethidine, and ephedrine findings. PMID:20617307

  3. Characterization of Disopyramide derivative ADD424042 as a non-cardiotoxic neuronal sodium channel blocker with broad-spectrum anticonvulsant activity in rodent seizure models.

    Science.gov (United States)

    Król, Marek; Ufnal, Marcin; Szulczyk, Bartłomiej; Podsadni, Piotr; Drapała, Adrian; Turło, Jadwiga; Dawidowski, Maciej

    2016-01-01

    It was reported that antiarrhythmic drugs (AADs) can be useful in controlling refractory seizures in humans or in enhancing the action of antiepileptic drugs (AEDs) in animal models. Disopyramide phosphate (DISO) is an AAD that blocks sodium channels in cardiac myocytes. We evaluated a DISO derivative, 2-(2-chlorophenyl)-2-(pyridin-2-yl)acetamide (ADD424042) for its anticonvulsant activity in a battery of rodent models of epileptic seizures. The compound displayed a broad spectrum of activity in the 'classical' models as well as in the models of pharmacoresistant seizures. Furthermore, ADD424042 showed good therapeutic indices between the anticonvulsant activity and the motor impairment. On the contrary, no anticonvulsant effects but severe lethality were observed in the primary anticonvulsant testing of the parent DISO. By performing the whole-cell voltage-clamp experiments in dispersed cortical neurons we demonstrated that ADD424042 decreased the maximal amplitude of voltage-gated sodium channels with an IC50 value in nM range. Moreover, the compound enhanced use-dependent block and decreased excitability in pyramidal neurons in the current-clamp experiments in cortical slices. Importantly, we found that ADD424042 possessed either no, or very small cardiotoxic effect. In contrast to DISO, ADD424042 did not produce any apparent changes in electrocardiogram (ECG) and arterial blood pressure recordings. ADD424042 had no effect on QT and corrected QT intervals, at a dose which was 15 times higher than ED50 for the anticonvulsant effect in the MES model. Taken together, these data suggest that ADD424042 has the potential to become a lead structure for novel broadly acting AEDs with wide margin of cardiac safety. PMID:26441377

  4. A natural component from Euphorbia humifusa Willd displays novel, broad-spectrum anti-influenza activity by blocking nuclear export of viral ribonucleoprotein.

    Science.gov (United States)

    Chang, So Young; Park, Ji Hoon; Kim, Young Ho; Kang, Jong Seong; Min, Ji-Young

    2016-03-01

    The need to develop anti-influenza drugs with novel antiviral mechanisms is urgent because of the rapid rate of antigenic mutation and the emergence of drug-resistant viruses. We identified a novel anti-influenza molecule by screening 861 plant-derived natural components using a high-throughput image-based assay that measures inhibition of the influenza virus infection. 1,3,4,6-tetra-O-galloyl-β-D-glucopyranoside (TGBG) from Euphorbia humifusa Willd showed broad-spectrum anti-influenza activity against two seasonal influenza A strains, A/California/07/2009 (H1N1) and A/Perth/16/2009 (H3N2), and seasonal influenza B strain B/Florida/04/2006. We investigated the mode of action of TGBG using neuraminidase activity inhibition and time-of-addition assays, which evaluate the viral release and entry steps, respectively. We found that TGBG exhibits a novel antiviral mechanism that differs from the FDA-approved anti-influenza drugs oseltamivir which inhibits viral release, and amantadine which inhibits viral entry. Immunofluorescence assay demonstrated that TGBG significantly inhibits nuclear export of influenza nucleoproteins (NP) during the early stages of infection causing NP to accumulate in the nucleus. In addition, influenza-induced activation of the Akt signaling pathway was suppressed by TGBG in a dose-dependent manner. These data suggest that a putative mode of action of TGBG involves inhibition of viral ribonucleoprotein (vRNP) export from the nucleus to the cytoplasm consequently disrupting the assembly of progeny virions. In summary, TGBG has potential as novel anti-influenza therapeutic with a novel mechanism of action. PMID:26850850

  5. WRR4, a broad-spectrum TIR-NB-LRR gene from Arabidopsis thaliana that confers white rust resistance in transgenic oilseed Brassica crops.

    Science.gov (United States)

    Borhan, Mohammad Hossein; Holub, Eric B; Kindrachuk, Colin; Omidi, Mansour; Bozorgmanesh-Frad, Ghazaleh; Rimmer, S Roger

    2010-03-01

    White blister rust caused by Albugo candida (Pers.) Kuntze is a common and often devastating disease of oilseed and vegetable brassica crops worldwide. Physiological races of the parasite have been described, including races 2, 7 and 9 from Brassica juncea, B. rapa and B. oleracea, respectively, and race 4 from Capsella bursa-pastoris (the type host). A gene named WRR4 has been characterized recently from polygenic resistance in the wild brassica relative Arabidopsis thaliana (accession Columbia) that confers broad-spectrum white rust resistance (WRR) to all four of the above Al. candida races. This gene encodes a TIR-NB-LRR (Toll-like/interleukin-1 receptor-nucleotide binding-leucine-rich repeat) protein which, as with other known functional members in this subclass of intracellular receptor-like proteins, requires the expression of the lipase-like defence regulator, enhanced disease susceptibility 1 (EDS1). Thus, we used RNA interference-mediated suppression of EDS1 in a white rust-resistant breeding line of B. napus (transformed with a construct designed from the A. thaliana EDS1 gene) to determine whether defence signalling via EDS1 is functionally intact in this oilseed brassica. The eds1-suppressed lines were fully susceptible following inoculation with either race 2 or 7 isolates of Al. candida. We then transformed white rust-susceptible cultivars of B. juncea (susceptible to race 2) and B. napus (susceptible to race 7) with the WRR4 gene from A. thaliana. The WRR4-transformed lines were resistant to the corresponding Al. candida race for each host species. The combined data indicate that WRR4 could potentially provide a novel source of white rust resistance in oilseed and vegetable brassica crops.

  6. Development of a monoclonal antibody specific to envelope domain III with broad-spectrum detection of all four dengue virus serotypes.

    Science.gov (United States)

    Kim, Sae-Hae; Kim, Yu Na; Truong, Thang Thua; Thu Thuy, Nguyen Thi; Mai, Le Quynh; Jang, Yong-Suk

    2016-05-13

    Dengue virus (DENV) is a mosquito-borne pathogen that annually infects more than 390 million people in 100 different countries. Symptoms of the viral infection include a relatively weak dengue fever to severe dengue hemorrhagic fever/dengue shock syndrome, which are mortal infectious diseases. As of yet, there is no commercially available vaccine or therapeutic for DENV. Currently, passive immunotherapy using DENV-specific antibody (Ab) is a considered strategy to treat DENV infection. Here, we developed a monoclonal Ab (mAb), EDIIImAb-61, specific to the DENV domain III of the envelope glycoprotein (EDIII) with broad-spectrum detection ability to all four DENV serotypes (DENV-1∼4) to use as a therapeutic Ab. Although EDIII contains non-immunodominant epitopes compared to domains I and II, domain III plays a critical role in host receptor binding. EDIIImAb-61 exhibited cross-reactive binding affinity to all four DENV serotypes that had been isolated from infected humans. To further characterize EDIIImAb-61 and prepare genes for large-scale production using a heterologous expression system, the sequence of the complementarity determining regions was analyzed after cloning the full-length cDNA genes encoding the heavy and light chain of the mAb. Finally, we produced Ab from CHO-K1 cells transfected with the cloned EDIIImAb-61 heavy and light chain genes and confirmed the binding ability of the Ab. Collectively, we conclude that EDIIImAb-61 itself and the recombinant Ab produced using the cloned heavy and light chain gene of EDIIImAb-61 is a candidate for passive immunotherapy against DENV infection. PMID:27059141

  7. Natural herbicide resistance (HR) to broad-spectrum herbicide, glyphosate among traditional and inbred-cultivated rice (Oryza sativa L.) varieties in Sri Lanka.

    Science.gov (United States)

    Weerakoon, S R; Somaratne, S; Wijeratne, R G D; Ekanyaka, E M S I

    2013-08-15

    Weeds along with insect pests and plant diseases are sources of biotic stress in crop systems. Weeds are responsible for serious problems in rice worldwide affecting growth and causing a considerable reduction in quality and quantity in yield. High concentrations of pre-emergent-broad-spectrum systemic herbicide, Glyphosate is prevalently applied to control rice weeds which intern causes severe damages to cultivated rice varieties, susceptible to Glyphosate. However, there may be rice varieties with natural Herbicide Resistance (HR) which are so far, has not been evaluated. In this study Six traditional and eighteen developed-cultivated rice varieties (Bg, Bw, At and Ld series developed by Rice Research Development Institute, Sri Lanka) were used to screen their natural HR. RCBD with five replicates and three blocks in each treatment-combination was used as the experimental design. As observations, time taken-to seed germination, time taken to flowering; plant height and number of leaves at 12-weeks after sawing, leaf-length, breadth, panicle-length, number of seeds/panicle of resistant plants and controls were recorded. Plants with > or = 40% resistance were considered as resistant to Glyphosate. Ten inbred-cultivated rice varieties (Bg250, Bg94-1, Bg304, Bg359, Bg406, Bg379-2, Bg366, Bg300, Bw364, At362) and three traditional rice varieties ("Kalu Heenati", "Sudu Heenati", "Pachchaperumal") were naturally resistant to 0.25 g L(-1) Glyphosate concentration and when increased the concentration (0.5 g L(-1)) resistance was reduced. This study showed the usefulness of modern statistical method, classification and regression tree analysis (CART) in exploring and visualizing the patterns reflected by a large number of rice varieties (larger experimental database) on herbicide resistance in future. PMID:24498832

  8. Linear biocompatible glyco-polyamidoamines as dual action mode virus infection inhibitors with potential as broad-spectrum microbicides for sexually transmitted diseases

    Science.gov (United States)

    Mauro, Nicolò; Ferruti, Paolo; Ranucci, Elisabetta; Manfredi, Amedea; Berzi, Angela; Clerici, Mario; Cagno, Valeria; Lembo, David; Palmioli, Alessandro; Sattin, Sara

    2016-09-01

    The initial steps of viral infections are mediated by interactions between viral proteins and cellular receptors. Blocking the latter with high-affinity ligands may inhibit infection. DC-SIGN, a C-type lectin receptor expressed by immature dendritic cells and macrophages, mediates human immunodeficiency virus (HIV) infection by recognizing mannose clusters on the HIV-1 gp120 envelope glycoprotein. Mannosylated glycodendrimers act as HIV entry inhibitors thanks to their ability to block this receptor. Previously, an amphoteric, but prevailingly cationic polyamidoamine named AGMA1 proved effective as infection inhibitor for several heparan sulfate proteoglycan-dependent viruses, such as human papilloma virus HPV-16 and herpes simplex virus HSV-2. An amphoteric, but prevailingly anionic PAA named ISA23 proved inactive. It was speculated that the substitution of mannosylated units for a limited percentage of AGMA1 repeating units, while imparting anti-HIV activity, would preserve the fundamentals of its HPV-16 and HSV-2 infection inhibitory activity. In this work, four biocompatible linear PAAs carrying different amounts of mannosyl-triazolyl pendants, Man-ISA7, Man-ISA14, Man-AGMA6.5 and Man-AGMA14.5, were prepared by reaction of 2-(azidoethyl)-α-D-mannopyranoside and differently propargyl-substituted AGMA1 and ISA23. All mannosylated PAAs inhibited HIV infection. Both Man-AGMA6.5 and Man-AGMA14.5 maintained the HPV-16 and HSV-2 activity of the parent polymer, proving broad-spectrum, dual action mode virus infection inhibitors.

  9. Mycophenolic acid, an immunomodulator, has potent and broad-spectrum in vitro antiviral activity against pandemic, seasonal and avian influenza viruses affecting humans.

    Science.gov (United States)

    To, Kelvin K W; Mok, Ka-Yi; Chan, Andy S F; Cheung, Nam N; Wang, Pui; Lui, Yin-Ming; Chan, Jasper F W; Chen, Honglin; Chan, Kwok-Hung; Kao, Richard Y T; Yuen, Kwok-Yung

    2016-08-01

    Immunomodulators have been shown to improve the outcome of severe pneumonia. We have previously shown that mycophenolic acid (MPA), an immunomodulator, has antiviral activity against influenza A/WSN/1933(H1N1) using a high-throughput chemical screening assay. This study further investigated the antiviral activity and mechanism of action of MPA against contemporary clinical isolates of influenza A and B viruses. The 50 % cellular cytotoxicity (CC50) of MPA in Madin Darby canine kidney cell line was over 50 µM. MPA prevented influenza virus-induced cell death in the cell-protection assay, with significantly lower IC50 for influenza B virus B/411 than that of influenza A(H1N1)pdm09 virus H1/415 (0.208 vs 1.510 µM, P=0.0001). For H1/415, MPA interfered with the early stage of viral replication before protein synthesis. For B/411, MPA may also act at a later stage since MPA was active against B/411 even when added 12 h post-infection. Virus-yield reduction assay showed that the replication of B/411 was completely inhibited by MPA at concentrations ≥0.78 µM, while there was a dose-dependent reduction of viral titer for H1/415. The antiviral effect of MPA was completely reverted by guanosine supplementation. Plaque reduction assay showed that MPA had antiviral activity against eight different clinical isolates of A(H1N1), A(H3N2), A(H7N9) and influenza B viruses (IC50 <1 µM). In summary, MPA has broad-spectrum antiviral activity against human and avian-origin influenza viruses, in addition to its immunomodulatory activity. Together with a high chemotherapeutic index, the use of MPA as an antiviral agent should be further investigated in vivo. PMID:27259985

  10. Inhibition of hemorrhagic and edematogenic activities of snake venoms by a broad-spectrum protease inhibitor, murinoglobulin; the effect on venoms from five different genera in Viperidae family.

    Science.gov (United States)

    Ribeiro Filho, Wilker; Sugiki, Masahiko; Yoshida, Etsuo; Maruyama, Masugi

    2003-08-01

    In order to obtain basic data on the effect of broad-spectrum protease inhibitor against local symptoms of Viperidae snake envenomation, inhibitory capacity of rat murinoglobulin on local hemorrhagic and edematogenic activities of venoms from Crotalus atrox, Bothrops jararaca, Lachesis muta muta, Trimeresurus flavoviridis and Echis carinatus sochureki were examined. Murinoglobulin, pre-incubated with the crude venoms at 37 degrees C for 15 min, inhibited hemorrhagic activity of all five venoms to various extents. The activity of C. atrox was almost completely inhibited at the murinoglobulin/venom ratio (w/w) of 20. The activity of B. jararaca, Lachesis muta muta and T. flavoviridis venoms was considerably inhibited at the ratio of 20 (77.2, 80.0 and 86.2% inhibition, respectively), however some of the activity still remained even at the ratio of 40 (84.2, 79.8 and 86.2% inhibition, respectively). Among the five venoms, E. c. sochureki venom is quite resistant to murinoglobulin treatment and statistically significant inhibition was only found at the ratio of 40 (64.1% inhibition). Fibrinolytic and gelatinase activities were more susceptible to murinoglobulin inhibition. The treatment at the ratios of 10 and 20 almost completely inhibited respectively the fibrinolytic and the gelatinase activities of all the venoms. Murinoglobulin treatment also significantly inhibited the edematogenic activity of L. muta muta, T. flavoviridis and Echis carinatus sochureki. The treatment of murinoglobulin at the ratio of 40 considerably suppressed the swelling up to 60 min after subcutaneous injection of L. muta muta and E. c. sochureki venoms, and up to 30 min after T. flavoviridis venom injection. Murinoglobulin is a potent inhibitor against local effects of multiple snake venoms in Viperidae family. PMID:12906888

  11. A novel, selective inhibitor of fibroblast growth factor receptors that shows a potent broad spectrum of antitumor activity in several tumor xenograft models.

    Science.gov (United States)

    Zhao, Genshi; Li, Wei-Ying; Chen, Daohong; Henry, James R; Li, Hong-Yu; Chen, Zhaogen; Zia-Ebrahimi, Mohammad; Bloem, Laura; Zhai, Yan; Huss, Karen; Peng, Sheng-Bin; McCann, Denis J

    2011-11-01

    The fibroblast growth factor receptors (FGFR) are tyrosine kinases that are present in many types of endothelial and tumor cells and play an important role in tumor cell growth, survival, and migration as well as in maintaining tumor angiogenesis. Overexpression of FGFRs or aberrant regulation of their activities has been implicated in many forms of human malignancies. Therefore, targeting FGFRs represents an attractive strategy for development of cancer treatment options by simultaneously inhibiting tumor cell growth, survival, and migration as well as tumor angiogenesis. Here, we describe a potent, selective, small-molecule FGFR inhibitor, (R)-(E)-2-(4-(2-(5-(1-(3,5-Dichloropyridin-4-yl)ethoxy)-1H-indazol-3yl)vinyl)-1H-pyrazol-1-yl)ethanol, designated as LY2874455. This molecule is active against all 4 FGFRs, with a similar potency in biochemical assays. It exhibits a potent activity against FGF/FGFR-mediated signaling in several cancer cell lines and shows an excellent broad spectrum of antitumor activity in several tumor xenograft models representing the major FGF/FGFR relevant tumor histologies including lung, gastric, and bladder cancers and multiple myeloma, and with a well-defined pharmacokinetic/pharmacodynamic relationship. LY2874455 also exhibits a 6- to 9-fold in vitro and in vivo selectivity on inhibition of FGF- over VEGF-mediated target signaling in mice. Furthermore, LY2874455 did not show VEGF receptor 2-mediated toxicities such as hypertension at efficacious doses. Currently, this molecule is being evaluated for its potential use in the clinic.

  12. Antimicrobial-Coated Granules for Disinfecting Water

    Science.gov (United States)

    Akse, James R.; Holtsnider, John T.; Kliestik, Helen

    2011-01-01

    Methods of preparing antimicrobialcoated granules for disinfecting flowing potable water have been developed. Like the methods reported in the immediately preceding article, these methods involve chemical preparation of substrate surfaces (in this case, the surfaces of granules) to enable attachment of antimicrobial molecules to the surfaces via covalent bonds. A variety of granular materials have been coated with a variety of antimicrobial agents that include antibiotics, bacteriocins, enzymes, bactericides, and fungicides. When employed in packed beds in flowing water, these antimicrobial-coated granules have been proven effective against gram-positive bacteria, gram-negative bacteria, fungi, and viruses. Composite beds, consisting of multiple layers containing different granular antimicrobial media, have proven particularly effective against a broad spectrum of microorganisms. These media have also proven effective in enhancing or potentiating the biocidal effects of in-line iodinated resins and of very low levels of dissolved elemental iodine.

  13. The Design and Construction of K11: A Novel α-Helical Antimicrobial Peptide

    Directory of Open Access Journals (Sweden)

    Huang Jin-Jiang

    2012-01-01

    Full Text Available Amphipathic α-helical antimicrobial peptides comprise a class of broad-spectrum agents that are used against pathogens. We designed a series of antimicrobial peptides, CP-P (KWKSFIKKLTSKFLHLAKKF and its derivatives, and determined their minimum inhibitory concentrations (MICs against Pseudomonas aeruginosa, their minimum hemolytic concentrations (MHCs for human erythrocytes, and the Therapeutic Index (MHC/MIC ratio. We selected the derivative peptide K11, which had the highest therapeutic index (320 among the tested peptides, to determine the MICs against Gram-positive and Gram-negative bacteria and 22 clinical isolates including Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Klebsiella pneumonia. K11 exhibited low MICs (less than 10 μg/mL and broad-spectrum antimicrobial activity, especially against clinically isolated drug-resistant pathogens. Therefore, these results indicate that K11 is a promising candidate antimicrobial peptide for further studies.

  14. Interaction between chlorhexidine digluconate and sodium monofluorophosphate in vitro

    International Nuclear Information System (INIS)

    The aim of the present study was to investigate the compatibility of chlorhexidine digluconate and sodium monofluorophosphate since these agents are potential ingredients in future products in preventive dentistry. Varying combinations of chlorhexidine digluconate and sodium monofluorophosphate in water, covering the possible ranges of clinically relevant concentrations of both compounds, were made, incubated for 24 h and observed for precipitation of insoluble salts. The mixtures were analyzed for presence of free chlorhexidine and monofluorophosphate after incubation. The results showed that chlorhexidine digluconate and sodium monofluorophosphate are not compatible in clinically relevant concentrations. A chlorhexidinemonofluorophosphate salt of low solubility in water is presumably formed. (author)

  15. Interaction between chlorhexidine digluconate and sodium monofluorophosphate in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Barkvoll, P.; Roella, G.; Bellagamba, S.

    1988-01-01

    The aim of the present study was to investigate the compatibility of chlorhexidine digluconate and sodium monofluorophosphate since these agents are potential ingredients in future products in preventive dentistry. Varying combinations of chlorhexidine digluconate and sodium monofluorophosphate in water, covering the possible ranges of clinically relevant concentrations of both compounds, were made, incubated for 24 h and observed for precipitation of insoluble salts. The mixtures were analyzed for presence of free chlorhexidine and monofluorophosphate after incubation. The results showed that chlorhexidine digluconate and sodium monofluorophosphate are not compatible in clinically relevant concentrations. A chlorhexidinemonofluorophosphate salt of low solubility in water is presumably formed.

  16. Chlorhexidine: Patient Bathing and Infection Prevention.

    Science.gov (United States)

    Abbas, Salma; Sastry, Sangeeta

    2016-08-01

    Healthcare-associated infections (HAIs) are an important cause of morbidity and mortality in the USA. They are associated with a substantial increase in health care costs each year. Fortunately, many HAIs are preventable, and their eradication is a national priority. Chlorhexidine (CHG) bathing has been used as an infection prevention measure, either alone or bundled with other interventions, with mostly beneficial results. The recent surge in its use as an agent of choice for skin antisepsis has lead to concerns over emerging resistance among microorganisms. Moreover, compliance with CHG-bathing protocols is not routinely monitored. Policies developed to determine the best infection prevention practice must consider that a "one-size-fits-all" strategy may lead to the selection of CHG-tolerant microorganisms, thereby emphasizing the need for more robust guidelines and additional studies on the role of chlorhexidine bathing for the prevention of HAIs.

  17. Delivery Challenges for Fluoride, Chlorhexidine and Xylitol

    OpenAIRE

    Featherstone, John DB

    2006-01-01

    The progression or reversal of dental caries is determined by the balance between pathological and protective factors. It is well established that a) fluoride inhibits demineralization and enhances remineralization, b) chlorhexidine reduces the cariogenic bacterial challenge, and c) xylitol is non-cariogenic and has antibacterial properties. The challenge that we face is how best to deliver these anti-caries entities at true therapeutic levels, over time, to favorably tip the caries balance. ...

  18. Cholic acid derivatives: novel antimicrobials.

    Science.gov (United States)

    Savage, P B; Li, C

    2000-02-01

    Mimics of squalamine and polymyxin B (PMB) have been prepared from cholic acid in hope of finding new antimicrobial agents. The squalamine mimics include the polyamine and sulphate functionalities found in the parent antibiotic, however, the positions relative to the steroid nucleus have been exchanged. The PMB mimics include the conservation of functionality among the polymyxin family of antibiotics, the primary amine groups and a hydrophobic chain. Although the squalamine and PMB mimics are morphologically dissimilar, they display similar activities. Both are simple to prepare and demonstrate broad spectrum antimicrobial activity against Gram-negative and Gram-positive organisms. Specific examples may be inactive alone, yet effectively permeabilise the outer membranes of Gram-negative bacteria rendering them sensitive to hydrophobic antibiotics. Problems associated with some of the squalamine and PMB mimics stem from their haemolytic activity and interactions with serum proteins, however, examples exist without these side effects which can sensitise Gram-negative bacteria to hydrophobic antibiotics. PMID:11060676

  19. Chlorhexidine and gauze and tape dressings for central venous catheters: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Edivane Pedrolo

    2014-10-01

    Full Text Available OBJECTIVE: to assess the effectiveness of the chlorhexidine antimicrobial dressing in comparison to the gauze and tape dressing in the use of central venous catheters.METHOD: a randomized clinical trial was conducted in the intensive care and adult semi intensive care units of a university hospital in the south of Brazil. The subjects were patients using short-term central venous catheters, randomly assigned to the intervention (chlorhexidine antimicrobial dressing or control (gauze and micro porous tape groups.RESULTS: a total of 85 patients were included: 43 in the intervention group and 42 in the control group. No statistically significant differences were found between dressings in regard to the occurrence of: primary bloodstream infections (p-value = 0.5170; local reactions to the dressing (p-value = 0.3774; and dressing fixation (p-value = 0.2739.CONCLUSION: both technologies are effective in covering central venous catheters in regard to the investigated variables and can be used for this purpose. Registry ECR: RBR-7b5ycz.

  20. Agonistic and Antagonistic Interactions between Chlorhexidine and Other Endodontic Agents: A Critical Review.

    Science.gov (United States)

    Mohammadi, Zahed; Giardino, Luciano; Palazzi, Flavio; Asgary, Saeed

    2015-01-01

    Root canal irrigants play a significant role in elimination of the microorganisms, tissue remnants, and removal of the debris and smear layer. No single solution is able to fulfill all these actions completely; therefore, a combination of irrigants may be required. The aim of this investigation was to review the agonistic and antagonistic interactions between chlorhexidine (CHX) and other irrigants and medicaments. An English-limited Medline search was performed for articles published from 2002 to 2014. The searched keywords included: chlorhexidine AND sodium hypochlorite/ethylenediaminetetraacetic acid/calcium hydroxide/mineral trioxide aggregate. Subsequently, a hand search was carried out on the references of result articles to find more matching papers. Findings showed that the combination of CHX and sodium hypochlorite (NaOCl) causes color changes and the formation of a neutral and insoluble precipitate; CHX forms a salt with ethylenediaminetetraacetic acid (EDTA). In addition, it has been demonstrated that the alkalinity of calcium hydroxide (CH) remained unchanged after mixing with CHX. Furthermore, mixing CHX with CH may enhance its antimicrobial activity; also mixing mineral trioxide aggregate (MTA) powder with CHX increases its antimicrobial activity but this may negatively affect its mechanical properties. PMID:25598802

  1. Enhanced chlorhexidine skin penetration with eucalyptus oil

    Directory of Open Access Journals (Sweden)

    Worthington Tony

    2010-09-01

    Full Text Available Abstract Background Chlorhexidine digluconate (CHG is a widely used skin antiseptic, however it poorly penetrates the skin, limiting its efficacy against microorganisms residing beneath the surface layers of skin. The aim of the current study was to improve the delivery of chlorhexidine digluconate (CHG when used as a skin antiseptic. Method Chlorhexidine was applied to the surface of donor skin and its penetration and retention under different conditions was evaluated. Skin penetration studies were performed on full-thickness donor human skin using a Franz diffusion cell system. Skin was exposed to 2% (w/v CHG in various concentrations of eucalyptus oil (EO and 70% (v/v isopropyl alcohol (IPA. The concentration of CHG (μg/mg of skin was determined to a skin depth of 1500 μm by high performance liquid chromatography (HPLC. Results The 2% (w/v CHG penetration into the lower layers of skin was significantly enhanced in the presence of EO. Ten percent (v/v EO in combination with 2% (w/v CHG in 70% (v/v IPA significantly increased the amount of CHG which penetrated into the skin within 2 min. Conclusion The delivery of CHG into the epidermis and dermis can be enhanced by combination with EO, which in turn may improve biocide contact with additional microorganisms present in the skin, thereby enhancing antisepsis.

  2. Chlorhexidine alcohol base mouthrinse versus Chlorhexidine formaldehyde base mouthrinse efficacy on plaque control: double blind, randomized clinical trials

    OpenAIRE

    Ennibi, Oumkeltoum; Lakhdar, Leila; Bouziane, Amal; Bensouda, Yahia; Abouqal, Redouane

    2013-01-01

    Background: Chlorhexidine is well known for its antiplaque effect. However, the mouthrinse based chlorhexidine antiplaque efficiency may vary according to the formulation of the final product. The aim of the present study was to compare anti-plaque effectiveness of two commercial mouthrinses: 0.12 % Chlorhexidine alcohol base (CLX-A) versus a diluted 0.1% Chlorhexidine non-alcohol base with 0.1% of Formaldehyde (CLX-F). Material and Methods: the study was a seven day randomized, double-blind,...

  3. In vitro effect of chlorhexidine mouth rinses on polyspecies biofilms.

    Science.gov (United States)

    Guggenheim, Bernhard; Meier, Andräé

    2011-01-01

    The aim of this study was to use the Zurich polyspecies biofilm model to compare the antimicrobial effects of chlorhexidine mouth rinses available on the Swiss market. As positive and negative controls, aqueous 0.15% CHX solution and water were used, respectively. In addition, Listerine® without CHX was tested. Biofilms in batch culture were grown in 24- well polystyrene tissue culture plates on hydroxyapatite discs in 70% mixed (1:1 diluted) unstimulated saliva and 30% complex culture medium. During the 64.5-hour culturing period, the biofilms were exposed to the test solutions for 1 minute twice a day on two subsequent days. Thereafter, the biofilms were dip-washed 3 times in physiological NaCl. Following the last exposure, the incubation of biofilms was continued for another 16 h. They were then harvested at 64.5 h. The dispersed biofilms were plated on 2 agar media. After incubation, colonies (CFU) were counted. All solutions containing CHX as well as Listerine ® significantly reduced the number of microorganisms in biofilms. According to their efficacy, the mouth rinses were classified into 2 groups. The two Curasept ADS solutions, Parodentosan, and the Listerine® mouth rinse reduced the number of total CFU by 3 log10 steps. This seems sufficient for a long-lasting prophylactic application. The two PlakOut® mouth rinses and the CHX control fell into the other group, where the number of CFU was reduced by 7 log10 steps. These mouth rinses are predestined for short-term therapeutic use. However, reversible side effects must be taken into account. It has thus far not been possible to formulate CHX products with effective ADS (Anti Discoloration System) additives without reducing antimicrobial activity. PMID:21656386

  4. Comparative evaluation of subgingivally delivered chlorhexidine varnish and chlorhexidine gel in reducing microbial count after mechanical periodontal therapy

    Science.gov (United States)

    Manthena, Sathish; Ramesh, Amitha; Srikanth, Adusumilli; Ramoji Rao, M. V.; Preethi, P. Lakshmi; Samatha, Y. Pallavi

    2014-01-01

    Context: Antimicrobial efficacy of subgingival chlorhexidine (CHX) application using two different vehicles of delivery. Aims: The aim was to evaluate the efficacy of CHX varnish and gel as an adjunct to scaling and root planing (SRP) in reducing microbial count within moderate to deep periodontal pockets. Settings and Design: Experimental parallel mouth study. Subjects and Methods: A total of 30 subjects between the age groups 25 and 55 years having moderate to severe periodontitis, with pocket depth ≥ 5 mm were selected for the study. The selected patients were randomized into three groups of 10 each. Subjects in Group 1 received SRP followed by subgingival application of CHX varnish, subjects in Group 2 received SRP followed by subgingival application of CHX gel, subjects in Group 3 received SRP alone. Subgingival plaque samples were collected to estimate mean motile and nonmotile microbial counts using dark field microscopy at baseline, 1 week, 1 month, and 3 months. Results: After 3 months, there was statistically significant reduction in nonmotile microbial count in all the three groups. Motile microbial count was significantly reduced in all the three groups till 1 month from baseline. Only subjects in Group 1 who received subgingival CHXvarnish after SRP showed a significant reduction in motile microbial count till 3 months from baseline. Conclusions: Subgingival application of highly concentrated CHX varnish following SRP is beneficial in reducing microbial count in moderate to deep periodontal pockets. PMID:25538468

  5. Environmental fate of herbicides trifluralin, metazachlor, metamitron and sulcotrione compared with that of glyphosate, a substitute broad spectrum herbicide for different glyphosate-resistant crops.

    Science.gov (United States)

    Mamy, Laure; Barriuso, Enrique; Gabrielle, Benoît

    2005-09-01

    The introduction of crops resistant to the broad spectrum herbicide glyphosate, N-(phosphonomethyl)glycine, may constitute an answer to increased contamination of the environment by herbicides, since it should reduce the total amount of herbicide needed and the number of active ingredients. However, there are few published data comparing the fate of glyphosate in the environment, particularly in soil, with that of substitute herbicides. The objective of this study is to compare the fate of glyphosate in three soils with that of four herbicides frequently used on crops that might be glyphosate resistant: trifluralin, alpha,alpha,alpha-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine, and metazachlor, 2-chloro-N-(pyrazol-1-ylmethyl)acet-2',6'-xylidide for oilseed rape, metamitron, 4-amino-4,5-dihydro-3-methyl-6-phenyl-1,2,4-triazin-5-one for sugarbeet and sulcotrione, 2-(2-chloro-4-mesylbenzoyl)cyclohexane-1,3-dione for maize. The distribution of herbicides between the volatilized, mineralized, extractable and non-extractable fractions was studied, along with the formation of their metabolites in laboratory experiments using 14C-labelled herbicides, over a period of 140 days. The main dissipation pathways were mineralization for glyphosate and sulcotrione, volatilization for trifluralin and non-extractable residues formation for metazachlor and metamitron. The five herbicides had low persistence. Glyphosate had the shortest half-life, which varied with soil type, whereas trifluralin had the longest. The half-lives of metazachlor and sulcotrione were comparable, whereas that of metamitron was highly variable. Glyphosate, metazachlor and sulcotrione were degraded into persistent metabolites. Low amounts of trifluralin and metamitron metabolites were observed. At 140 days after herbicide applications, the amounts of glyphosate and its metabolite residues in soils were the lowest in two soils, but not in the third soil, a loamy sand with low pH. The environmental advantage

  6. The landscape of host transcriptional response programs commonly perturbed by bacterial pathogens: towards host-oriented broad-spectrum drug targets.

    Directory of Open Access Journals (Sweden)

    Yared H Kidane

    Full Text Available BACKGROUND: The emergence of drug-resistant pathogen strains and new infectious agents pose major challenges to public health. A promising approach to combat these problems is to target the host's genes or proteins, especially to discover targets that are effective against multiple pathogens, i.e., host-oriented broad-spectrum (HOBS drug targets. An important first step in the discovery of such drug targets is the identification of host responses that are commonly perturbed by multiple pathogens. RESULTS: In this paper, we present a methodology to identify common host responses elicited by multiple pathogens. First, we identified host responses perturbed by each pathogen using a gene set enrichment analysis of publicly available genome-wide transcriptional datasets. Then, we used biclustering to identify groups of host pathways and biological processes that were perturbed only by a subset of the analyzed pathogens. Finally, we tested the enrichment of each bicluster in human genes that are known drug targets, on the basis of which we elicited putative HOBS targets for specific groups of bacterial pathogens. We identified 84 up-regulated and three down-regulated statistically significant biclusters. Each bicluster contained a group of pathogens that commonly dysregulated a group of biological processes. We validated our approach by checking whether these biclusters correspond to known hallmarks of bacterial infection. Indeed, these biclusters contained biological process such as inflammation, activation of dendritic cells, pro- and anti- apoptotic responses and other innate immune responses. Next, we identified biclusters containing pathogens that infected the same tissue. After a literature-based analysis of the drug targets contained in these biclusters, we suggested new uses of the drugs Anakinra, Etanercept, and Infliximab for gastrointestinal pathogens Yersinia enterocolitica, Helicobacter pylori kx2 strain, and enterohemorrhagic Escherichia

  7. Synthesis, Characterization, and In Vitro and In Vivo Evaluations of 4-(N-Docosahexaenoyl 2′, 2′-Difluorodeoxycytidine with Potent and Broad-Spectrum Antitumor Activity

    Directory of Open Access Journals (Sweden)

    Youssef W. Naguib

    2016-01-01

    Full Text Available In this study, a new compound, 4-(N-docosahexaenoyl 2′, 2′-difluorodeoxycytidine (DHA-dFdC, was synthesized and characterized. Its antitumor activity was evaluated in cell culture and in mouse models of pancreatic cancer. DHA-dFdC is a poorly soluble, pale yellow waxy solid, with a molecular mass of 573.3 Da and a melting point of about 96°C. The activation energy for the degradation of DHA-dFdC in an aqueous Tween 80–based solution is 12.86 kcal/mol, whereas its stability is significantly higher in the presence of vitamin E. NCI-60 DTP Human Tumor Cell Line Screening revealed that DHA-dFdC has potent and broad-spectrum antitumor activity, especially in leukemia, renal, and central nervous system cancer cell lines. In human and murine pancreatic cancer cell lines, the IC50 value of DHA-dFdC was up to 105-fold lower than that of dFdC. The elimination of DHA-dFdC in mouse plasma appeared to follow a biexponential model, with a terminal phase t1/2 of about 58 minutes. DHA-dFdC significantly extended the survival of genetically engineered mice that spontaneously develop pancreatic ductal adenocarcinoma. In nude mice with subcutaneously implanted human Panc-1 pancreatic tumors, the antitumor activity of DHA-dFdC was significantly stronger than the molar equivalent of dFdC alone, DHA alone, or the physical mixture of them (1:1, molar ratio. DHA-dFdC also significantly inhibited the growth of Panc-1 tumors orthotopically implanted in the pancreas of nude mice, whereas the molar equivalent dose of dFdC alone did not show any significant activity. DHA-dFdC is a promising compound for the potential treatment of cancers in organs such as the pancreas.

  8. Isolation of Lactic Acid Bacteria with Broad-Spectrum Antimicrobial Activity and Analysis of Antimicrobial Substances%具有广谱抑菌活性乳酸菌的筛选及抑菌物质分析

    Institute of Scientific and Technical Information of China (English)

    马妙莲; 赵静; 陈晓琳; 张付海; 朱敏; 张明

    2012-01-01

    A strain with strong inhibitory activity against Gram-positive bacteria,Gram-negative bacteria and mold,named as LPEM818,was isolated from Millet by the overlay plate method.The strain was identified as Lactobacillus pentosus by physiological and biochemical characterization and 16S rRNA sequence homology analysis.In the cell-free fermentation supernatant,some antimircrobial substances including lactic acid,acetic acid,succinic acid,citric acid,palmitic acid,oleic acid,stearic acid and linoleic acid were found by GC-MS and HPLC analyses.%采用双层平板法从食用小米中分离出一株对实验所测的革兰氏阳性菌、阴性菌和霉菌有明显抑制作用的菌株,通过生理生化特性和16S rRNA基因序列同源性分析,确定该菌株为戊糖乳杆菌(Lactobacillus pentosus)。经气相色谱-质谱联用仪和高效液相色谱初步分析该菌株发酵上清液中含有乳酸、乙酸、琥珀酸、柠檬酸、棕榈酸、油酸、硬脂酸和亚油酸等多种抑菌成分。

  9. FORMULATION OF CHLORHEXIDINE GLUCONATE DENTAL GELS AND ITS ANTIBACTERIAL ACTIVITY

    OpenAIRE

    Shivani Salil Desai; Patel, Vishnu M.

    2015-01-01

    Chlorhexidine has bacteriocidal and bacteriostatic properties also it is used to reduce oral bacteria and dental plaque. Chlorhexidine gluconate present in gel formulations possesses antibacterial activity towards the organisms present in the dental plaque. Hence, it is a new alternative and cheaper formulation for the treatment of Periodontitis.

  10. Antimicrobial activities of squalamine mimics.

    Science.gov (United States)

    Kikuchi, K; Bernard, E M; Sadownik, A; Regen, S L; Armstrong, D

    1997-07-01

    We investigated the antimicrobial properties of compounds with structural features that were designed to mimic those of squalamine, an antibiotic isolated from the stomach of the dogfish shark. The mimics, like squalamine, are sterol-polyamine conjugates. Unlike squalamine, the mimics were simple to prepare, at high yield, from readily available starting materials. Several squalamine mimics showed activity against gram-negative rods, gram-positive cocci including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, and fungi. Some had little or no hemolytic activity. The hydrophobicity of the sterol backbone and the length and the cationic charge of the side chains appeared to be critical determinants of activity. One of the squalamine mimics, SM-7, was bactericidal against Escherichia coli, Pseudomonas aeruginosa, and S. aureus; its activity was decreased by divalent or monovalent cations and by bovine serum albumin. Subinhibitory concentrations of SM-7 markedly enhanced the antimicrobial activity of rifampin against gram-negative rods. These results suggest that the compounds may disrupt an outer membrane of gram-negative rods. Squalamine mimics are a new class of broad-spectrum antimicrobial agents. The antagonism of their activity by serum and albumin and their hemolytic properties may limit their use as systemic agents. The squalamine mimics, because of their potencies, broad spectra of antimicrobial activity, and potential for systemic toxicity, appear to be good candidates for development as topical antimicrobial agents. PMID:9210661

  11. Anaphylactic reactions in anaesthetised patients - four cases of chlorhexidine allergy

    DEFF Research Database (Denmark)

    Garvey, L H; Roed-Petersen, J; Husum, B

    2001-01-01

    Chlorhexidine is widely used all over the world in many different preparations. In Denmark chlorhexidine is the standard skin disinfectant used before surgery or invasive procedures and it is widely used in the general population in mouthwash or for disinfection of minor scratches etc. The potent......Chlorhexidine is widely used all over the world in many different preparations. In Denmark chlorhexidine is the standard skin disinfectant used before surgery or invasive procedures and it is widely used in the general population in mouthwash or for disinfection of minor scratches etc...... into the operation and all four patients required treatment with adrenaline. All four patients had a history of minor symptoms like rashes or faints in connection with previous surgery/invasive procedures. Allergy to chlorhexidine may be more prevalent in surgical patients and cases may have been overlooked due...

  12. A Sequential Statistical Approach towards an Optimized Production of a Broad Spectrum Bacteriocin Substance from a Soil Bacterium Bacillus sp. YAS 1 Strain

    Directory of Open Access Journals (Sweden)

    Amira M. Embaby

    2014-01-01

    Full Text Available Bacteriocins, ribosomally synthesized antimicrobial peptides, display potential applications in agriculture, medicine, and industry. The present study highlights integral statistical optimization and partial characterization of a bacteriocin substance from a soil bacterium taxonomically affiliated as Bacillus sp. YAS 1 after biochemical and molecular identifications. A sequential statistical approach (Plackett-Burman and Box-Behnken was employed to optimize bacteriocin (BAC YAS 1 production. Using optimal levels of three key determinants (yeast extract (0.48% (w/v, incubation time (62 hrs, and agitation speed (207 rpm in peptone yeast beef based production medium resulted in 1.6-fold enhancement in BAC YAS 1 level (470 AU/mL arbitrary units against Erwinia amylovora. BAC YAS 1 showed activity over a wide range of pH (1–13 and temperature (45–80°C. A wide spectrum antimicrobial activity of BAC YAS 1 against the human pathogens (Clostridium perfringens, Staphylococcus epidermidis, Campylobacter jejuni, Enterobacter aerogenes, Enterococcus sp., Proteus sp., Klebsiella sp., and Salmonella typhimurium, the plant pathogen (E. amylovora, and the food spoiler (Listeria innocua was demonstrated. On top and above, BAC YAS 1 showed no antimicrobial activity towards lactic acid bacteria (Lactobacillus bulgaricus, L. casei, L. lactis, and L. reuteri. Promising characteristics of BAC YAS 1 prompt its commercialization for efficient utilization in several industries.

  13. A sequential statistical approach towards an optimized production of a broad spectrum bacteriocin substance from a soil bacterium Bacillus sp. YAS 1 strain.

    Science.gov (United States)

    Embaby, Amira M; Heshmat, Yasmin; Hussein, Ahmed; Marey, Heba S

    2014-01-01

    Bacteriocins, ribosomally synthesized antimicrobial peptides, display potential applications in agriculture, medicine, and industry. The present study highlights integral statistical optimization and partial characterization of a bacteriocin substance from a soil bacterium taxonomically affiliated as Bacillus sp. YAS 1 after biochemical and molecular identifications. A sequential statistical approach (Plackett-Burman and Box-Behnken) was employed to optimize bacteriocin (BAC YAS 1) production. Using optimal levels of three key determinants (yeast extract (0.48% (w/v), incubation time (62 hrs), and agitation speed (207 rpm)) in peptone yeast beef based production medium resulted in 1.6-fold enhancement in BAC YAS 1 level (470 AU/mL arbitrary units against Erwinia amylovora). BAC YAS 1 showed activity over a wide range of pH (1-13) and temperature (45-80 °C). A wide spectrum antimicrobial activity of BAC YAS 1 against the human pathogens (Clostridium perfringens, Staphylococcus epidermidis, Campylobacter jejuni, Enterobacter aerogenes, Enterococcus sp., Proteus sp., Klebsiella sp., and Salmonella typhimurium), the plant pathogen (E. amylovora), and the food spoiler (Listeria innocua) was demonstrated. On top and above, BAC YAS 1 showed no antimicrobial activity towards lactic acid bacteria (Lactobacillus bulgaricus, L. casei, L. lactis, and L. reuteri). Promising characteristics of BAC YAS 1 prompt its commercialization for efficient utilization in several industries.

  14. The effect of chlorhexidine dentifrice or gel versus chlorhexidine mouthwash on plaque, gingivitis, bleeding and tooth discoloration: a systematic review

    NARCIS (Netherlands)

    S.C. Supranoto; D.E. Slot; M. Addy; G.A. van der Weijden

    2015-01-01

    Objective To systematically review and evaluate the available scientific evidence on the effectiveness of chlorhexidine dentifrice or gel (CHX DF/gel) compared to chlorhexidine mouthwash (CHX MW) on plaque, bleeding, gingival inflammation and tooth discoloration scores. Material and methods PubMed-M

  15. A New Derivative of Valproic Acid Amide Possesses a Broad-spectrum Antiseizure Profile and Unique Activity Against Status Epilepticus and Organophosphate Neuronal Damage

    Science.gov (United States)

    White, H. Steve; Alex, Anitha B.; Pollock, Amanda; Hen, Naama; Shekh-Ahmad, Tawfeeq; Wilcox, Karen S.; McDonough, John H.; Stables, James P.; Kaufmann, Dan; Yagen, Boris; Bialer, Meir

    2011-01-01

    displayed anticonvulsant activity in the rat pilocarpine model of SE. Thirty minutes after the induction of SE, the calculated rat-ED50 for SPD against convulsive SE in this model was 84mg/kg. SPD was not neuroprotective in the organotypic hippocampal slice preparation; however, it did display hippocampal neuroprotection in both SE models and cognitive sparing in the MWM which was associated with its antiseizure effect against pilocarpine-induced SE. When administered 20 and 40min after SE onset, SPD (100-174mg/kg) produced long-lasting efficacy (e.g., 4-8hr) against soman-induced convulsive and electrographic SE in both rats and guinea pigs. SPD-ED50 values in guinea pigs were 67mg/kg and 92mg/kg at when administered at SE onset or 40min after SE onset, respectively. Assuming linear PK, the PK-PD results (rats) suggests that effective SPD plasma levels ranged between 8-40mg/L (20 min post onset of soman-induced seizures) and 12-50mg/L (40 min post onset of soman-induced seizures). The time to peak (tmax) pharmacodynamic effect (PD-tmax) occurred after the PK-tmax thereby suggesting that SPD undergoes slow distribution to extra-plasmatic sites likely responsible for SPD’s antiseizure activity. Significance The results demonstrate that SPD is a broad-spectrum antiseizure compound that blocks SE induced by pilocarpine and soman and affords in vivo neuroprotection that is associated with cognitive sparing. Its activity against SE is superior to diazepam in terms of rapid onset, potency and its effect on animal mortality and functional improvement. PMID:22150444

  16. Antimicrobial properties of Honduran medicinal plants.

    Science.gov (United States)

    Lentz, D L; Clark, A M; Hufford, C D; Meurer-Grimes, B; Passreiter, C M; Cordero, J; Ibrahimi, O; Okunade, A L

    1998-12-01

    Ninety-two plants used in the traditional pharmacopoeia of the Pech and neighboring Mestizo peoples of central Honduras are reported. The results of in vitro antimicrobial screens showed that 19 of the extracts from medicinal plants revealed signs of antifungal activity while 22 demonstrated a measurable inhibitory effect on one or more bacterial cultures. Bioassay-guided fractionation of extracts from Mikania micrantha, Neurolaena lobata and Piper aduncum produced weak to moderately active isolates. The broad spectrum of activity of the extracts helps to explain the widespread use of these plants for wound healing and other applications. PMID:10030730

  17. Evaluation of Antimicrobial Activity of Root Extracts of Abitulon indicum

    Directory of Open Access Journals (Sweden)

    Krishna Rao MORTHA

    2015-06-01

    Full Text Available Antimicrobial activity of Abitulon indicum roots was studied against seven pathogenic bacteria and three fungal strains by agar well diffusion method. Antimicrobial activity was recorded for hexane, chloroform, methanol, ethanol and aqueous extracts. Alcohol (ethanol and methanol extracts exhibited the highest degree of antimicrobial activity compared to aqueous, chloroform and hexane extracts. Pseudomonas aeruginosa was turned out to be the most susceptible bacterium to the crude root chemical constituents, using the standard Tetracycline and Clotrimazole. Minimum inhibition concentration values of hexane, chloroform, methanol, ethanol and aqueous extracts were determined by the agar dilution method and ranged between 62.5 and 1,000 µg. The study suggested that the root extracts possess bioactive compounds with antimicrobial activity against the tested bacteria and fungi, revealing a significant scope to develop a novel broad spectrum of antimicrobial drug formulation from Abitulon indicum.

  18. Mass Spectrometry Imaging of Chlorhexidine and Bacteria in a Model Wound

    Directory of Open Access Journals (Sweden)

    Timothy Hamerly

    2015-08-01

    Full Text Available The ability to generate two-dimensional images of a wound that contains information about the distribution of bacteria overlaid with the distribution of drugs and metabolites could enhance our understanding of wound healing processes. Advances in technology are leading to a rapid expansion in mass spectrometry-based imaging. When combined with the ability of matrix assisted laser desorption ionization to ionize a wide range of molecules, imaging mass spectrometry is a powerful biomedical research tool. However, this technique has yet to be used to investigate bacterial colonization of wounds or the distribution of antimicrobial agents on tissue. To address this, distribution and persistence of the antimicrobial agent chlorhexidine on a model human tissue was investigated. The ability to detect and localize Staphylococcus aureus on the same tissue model was also addressed. Sub-millimeter resolution ion images from these experiments show the promise of using mass spectrometry imaging to investigate the growth and treatment of bacteria on skin. This methodology will be of value in the development of wound dressings with improved antimicrobial properties and a more careful analysis of the concentration of antimicrobial agents required to prevent biofilm formation and persistence.

  19. Controlled Release of Chlorhexidine from UDMA-TEGDMA Resin

    OpenAIRE

    Anusavice, K.J.; Zhang, N.-Z.; Shen, C.

    2006-01-01

    Chlorhexidine salts are available in various formulations for dental applications. This study tested the hypothesis that the release of chlorhexidine from a urethane dimethacrylate and triethylene glycol dimethacrylate resin system can be effectively controlled by the chlorhexidine diacetate content and pH. The filler concentrations were 9.1, 23.1, or 33.3 wt%, and the filled resins were exposed to pH 4 and pH 6 acetate buffers. The results showed that Fickian diffusion was the dominant relea...

  20. Helical Antimicrobial Sulfono- {gamma} -AApeptides

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yaqiong; Wu, Haifan; Teng, Peng; Bai, Ge; Lin, Xiaoyang; Zuo, Xiaobing; Cao, Chuanhai; Cai, Jianfeng

    2015-06-11

    Host-defense peptides (HDPs) such as magainin 2 have emerged as potential therapeutic agents combating antibiotic resistance. Inspired by their structures and mechanism of action, herein we report the fi rst example of antimicrobial helical sulfono- γ - AApeptide foldamers. The lead molecule displays broad-spectrum and potent antimicrobial activity against multi-drug-resistant Gram- positive and Gram-negative bacterial pathogens. Time-kill studies and fl uorescence microscopy suggest that sulfono- γ -AApeptides eradicate bacteria by taking a mode of action analogous to that of HDPs. Clear structure - function relationships exist in the studied sequences. Longer sequences, presumably adopting more-de fi ned helical structures, are more potent than shorter ones. Interestingly, the sequence with less helical propensity in solution could be more selective than the stronger helix-forming sequences. Moreover, this class of antimicrobial agents are resistant to proteolytic degradation. These results may lead to the development of a new class of antimicrobial foldamers combating emerging antibiotic-resistant pathogens.

  1. Contamination of chlorhexidine cream used to prevent ascending urinary tract infections

    Energy Technology Data Exchange (ETDEWEB)

    Salveson, A.; Bergan, T.

    1981-06-01

    Chlorhexidine-containing cream is often used as an antimicrobial barrier to ascending urinary tract infection in patients with indwelling urethral catheters. The cream is dispensed in small tubes for personal use but repeated use of a tube still entails a potential infection hazard. The extent of cream contamination was analysed by emulsifying it in 1% peptone broth with 1% Tween-80 added as a wetting agent, and culturing quantitatively for bacteria and fungi by membrane filtration. Twenty-three per cent of cream samples and 35% of swabs taken from outside the tube beneath the screw cap demonstrated microbial contamination. Isolates included potential pathogens such as enterococci, staphylococci, Proteus mirabilis, Pseudomonas aeruginosa, opportunists like Moraxella spp. and diphtheroids, and contaminants such as Bacillus spp., micrococci, and a mould of the genus Cladosporium. Contamination of cream with a particular bacterial strain was found to precede urinary tract infection with the same microbe. We recommend that chlorhexidine cream for this use be dispensed in single dose units to ensure sterility.

  2. Isolation, purification and characterization of novel antimicrobial compound 7-methoxy-2,2-dimethyl-4-octa-4′,6′-dienyl-2H-napthalene-1-one from Penicillium sp. and its cytotoxicity studies

    OpenAIRE

    Kaur, Harpreet; Onsare, Jemimah Gesare; Sharma, Vishal; Arora, Daljit Singh

    2015-01-01

    Fungus isolated from soil has been evaluated for its antimicrobial activity which showed broad spectrum antimicrobial activity against all the pathogenic microorganisms used. Optimization was done by response surface methodology (RSM) to further optimize the medium which could further enhance the antimicrobial activity by 1.1–1.9 folds. Column chromatography was used to isolate the active compound which was characterized to be by various spectroscopic techniques such NMR, IR and LCMS and it w...

  3. Antiplaque effect of essential oils and 0.2% chlorhexidine on an in situ model of oral biofilm growth: a randomised clinical trial.

    Directory of Open Access Journals (Sweden)

    Víctor Quintas

    Full Text Available To evaluate the in situ antiplaque effect after 4 days of using of 2 commercial antimicrobial agents in short term on undisturbed plaque-like biofilm.An observer-masked, crossover randomised clinical trial on 15 oral and systemically healthy volunteers between 20-30 years who were randomly and sequentially allocated in the same group which performed 3 interventions in different randomised sequences.The participants wore an appliance in 3 different rinsing periods doing mouthwashes twice a day (1/0/1 with essential oils, 0.2% chlorhexidine or sterile water (negative control. At the end of each 4-day mouthwash period, samples were removed from the appliance. Posteriorly, after bacterial vital staining, samples were analysed using a Confocal Laser Scanning Microscope.Bacterial vitality, thickness and covering grade by the biofilm after 4 days of applying each of the mouthwashes.The essential oils and the 0.2% chlorhexidine were significantly more effective than the sterile water at reducing bacterial vitality, thickness and covering grade by the biofilm. No significant differences were found between the 0.2% chlorhexidine and the essential oils at reducing the bacterial vitality (13.2% vs. 14.7%. However, the 0.2% chlorhexidine showed more reduction than the essential oils in thickness (6.5 μm vs. 10.0 μm; p<0.05 and covering grade by the biofilm (20.0% vs. 54.3%; p<0.001.The essential oils and 0.2% chlorhexidine showed a high antiplaque effect. Although the 0.2% chlorhexidine showed better results with regard to reducing the thickness and covering grade by the biofilm, both antiseptics showed a high and similar antibacterial activity.Daily essential oils or 0.2% chlorhexidine mouthwashes are effective when reducing dental plaque formation in the short term. Although 0.2% chlorhexidine continues to be the "gold standard" in terms of antiplaque effect, essential oils could be considered a reliable alternative.ClinicalTrials.gov NCT02124655.

  4. Effect of chlorhexidine on bonding durability of two self-etching adhesives with and without antibacterial agent to dentin

    Directory of Open Access Journals (Sweden)

    Fereshteh Shafiei

    2013-01-01

    Conclusion: Chlorhexidine was capable of diminishing the loss of BS of these adhesives over time. However, considering the negative effect of chlorhexidine on the initial BS, the benefits of chlorhexidine associated with these adhesives cannot possibly be used.

  5. Efficacy evaluations on five chlorhexidine teat dip formulations.

    Science.gov (United States)

    Drechsler, P A; O'Neil, J K; Murdough, P A; Lafayette, A R; Wildman, E E; Pankey, J W

    1993-09-01

    Three developmental postmilking teat dip formulations containing chlorhexidine digluconate were evaluated against Staphylococcus aureus and Streptococcus agalactiae in sequential experimental exposure trials. Two additional commercial chlorhexidine digluconate teat dip products were evaluated in natural exposure trials. Under conditions of experimental challenge, the developmental formulations were efficacious against Staph. aureus but did not significantly reduce incidence of new IMI by Strep. agalactiae. None of the three formulations of a conventional germicide used as teat sanitizers effectively reduced incidence of new Strep. agalactiae IMI under experimental challenge conditions. In the natural exposure trials with negative controls, a .35% chlorhexidine teat sanitizer had efficacy of 88.7% against Staph. aureus and 51.4% against Strep. agalactiae. The .5% chlorhexidine product reduced Staph. aureus and Strep. agalactiae IMI by 86 and 56%, respectively. PMID:8227681

  6. Chlorhexidine, A Medicine for all the Oral Diseases

    Directory of Open Access Journals (Sweden)

    Radhika Gupta

    2012-03-01

    Full Text Available Chlorhexidine is a bisbiguanide antiseptic. It is active against both Gram-positive and Gram-negative strains as well as fungi. It has bacteriostatic and bactericidal actions. Chlorhexidine has excellent antiplaque activity and unique property of substantivity. So it has got wide applications starting from maintaining oral hygiene pre surgically to post operative and also in physically and mentally handicapped patients. Chlorhexidine is now routinely used by clinicians when they treat patients with fixed appliances in orthodontia and maxillofacial surgeries. Chlorhexidine has been extensively used in various medical fields such as gynecology, urology and ophthalmology; also in disinfection of operation fields and treatment of burns. Its products are available in various forms like mouth rinses, gels, sprays, toothpastes and varnishes.

  7. Antimicrobial peptides of multicellular organisms

    Science.gov (United States)

    Zasloff, Michael

    2002-01-01

    Multicellular organisms live, by and large, harmoniously with microbes. The cornea of the eye of an animal is almost always free of signs of infection. The insect flourishes without lymphocytes or antibodies. A plant seed germinates successfully in the midst of soil microbes. How is this accomplished? Both animals and plants possess potent, broad-spectrum antimicrobial peptides, which they use to fend off a wide range of microbes, including bacteria, fungi, viruses and protozoa. What sorts of molecules are they? How are they employed by animals in their defence? As our need for new antibiotics becomes more pressing, could we design anti-infective drugs based on the design principles these molecules teach us?

  8. Targeted chitosan-based bionanocomposites for controlled oral mucosal delivery of chlorhexidine.

    Science.gov (United States)

    Onnainty, Renée; Onida, Barbara; Páez, Paulina; Longhi, Marcela; Barresi, Antonello; Granero, Gladys

    2016-07-25

    The purpose of this study was to develop sustained release systems based on chitosan (CS) and montmorillonite (MMT) for chlorhexidine (CLX). Nanocomposites were prepared by ion-exchange. CLX systems were characterized by X-ray powder diffraction (XRD), thermal analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray fluorescence analysis (XRF). The mucoadhesion properties of CLX nanocomposites were evaluated by SEM. The release behavior of these systems was also studied by the dialysis technique. The antibacterial activity was investigated in vitro by the disk diffusion test. Results showed long-term sustained release of CLX from the hybrid carriers without initial burst release. The release profiles of CLX from the carriers suggested the diffusion through a swollen matrix and water filled pores as the controlled drug release mechanism. The CLX hybrid nanosystem containing the positively-charged chitosan exhibited good mucoadhesion properties maintaining the CLX antimicrobial properties. PMID:27282538

  9. Susceptibility of archaea to antimicrobial agents: applications to clinical microbiology.

    Science.gov (United States)

    Khelaifia, S; Drancourt, M

    2012-09-01

    We herein review the state of knowledge regarding the in vitro and in vivo susceptibility of archaea to antimicrobial agents, including some new molecules. Indeed, some archaea colonizing the human microbiota have been implicated in diseases such as periodontopathy. Archaea are characterized by their broad-spectrum resistance to antimicrobial agents. In particular, their cell wall lacks peptidoglycan, making them resistant to antimicrobial agents interfering with peptidoglycan biosynthesis. Archaea are, however, susceptible to the protein synthesis inhibitor fusidic acid and imidazole derivatives. Also, squalamine, an antimicrobial agent acting on the cell wall, proved effective against human methanogenic archaea. In vitro susceptibility data could be used to design protocols for the decontamination of complex microbiota and the selective isolation of archaea in anaerobic culture. PMID:22748132

  10. MRJP1-containing glycoproteins isolated from honey, a novel antibacterial drug candidate with broad spectrum activity against multi-drug resistant clinical isolates

    Directory of Open Access Journals (Sweden)

    Katrina eBrudzynski

    2015-07-01

    Full Text Available The emergence of extended- spectrum β-lactamase (ESBL is the underlying cause of growing antibiotic resistance among Gram-negative bacteria to β-lactam antibiotics. We recently reported the discovery of honey glycoproteins (glps that exhibited a rapid, concentration-dependent antibacterial activity against both Gram-positive Bacillus subtilis and Gram-negative Escherichia coli that resembled action of cell wall-active β-lactam drugs. Glps showed sequence identity with the Major Royal Jelly Protein 1 (MRJP1 precursor that harbors three antimicrobial peptides: Jelleins 1, 2 and 4. Here, we used semi-quantitative radial diffusion assay and broth microdilution assay to evaluate susceptibility of a number of multi-drug resistant (MDR clinical isolates to the MRJP1-contaning honey glycoproteins. The MDR bacterial strains comprised 3 MRSA, 4 Pseudomonas aeruginosa, 2 Klebsiella pneumoniae, 2 VRE and 5 Extended-spectrum beta-lactamase (ESBL identified as 1 Proteus mirabilis, 3 Escherichia coli and 1 Escherichia coli NDM. Their resistance to different classes of antibiotics was confirmed using automated system Vitek 2. MDR isolates differred in their susceptibility to glps with MIC90 values ranging from 4.8μg/ml against B. subtilis to 14.4μg/ml against ESBL K. pneumoniae, Klebsiella spp ESBL and E. coli and up to 33μg/ml against highly resistant strains of P. aeruginosa. Glps isolated from different honeys showed a similar ability to overcome bacterial resistance to β-lactams suggesting that (a their mode of action is distinct from other classes of β-lactams and that (b the common glps structure was the lead structure responsible for the activity. The results of the current study together with our previous evidence of a rapid bactericidal activity of glps demonstrate that glps possess suitable characteristics to be considered a novel antibacterial drug candidate.

  11. Preparation and evaluation of antimicrobial activity of nanosystems for the control of oral pathogens Streptococcus mutans and Candida albicans

    Directory of Open Access Journals (Sweden)

    Pupe CG

    2011-10-01

    Full Text Available Carolina Gonçalves Pupe1, Michele Villardi1, Carlos Rangel Rodrigues1, Helvécio Vinícius Antunes Rocha2, Lucianne Cople Maia3, Valeria Pereira de Sousa1, Lucio Mendes Cabral11Depto de Medicamentos, Faculdade de Farmácia, UFRJ, Rio de Janeiro, 2Farmanguinhos/FIOCRUZ, Rio de Janeiro, 3Faculdade de Odontologia, UFRJ, Rio de Janeiro, BrazilBackground: Diseases that affect the buccal cavity are a public health concern nowadays. Chlorhexidine and nystatin are the most commonly used drugs for the control of buccal affections. In the search for more effective antimicrobials, nanotechnology can be successfully used to improve the physical chemical properties of drugs whilst avoiding the undesirable side effects associated with its use. Herein described are studies using nystatin and chlorhexidine with sodium montmorillonite (MMTNa, and chlorhexidine with ß-cyclodextrin and two derivatives methyl-β-cyclodextrin and hydroxypropyl-β-cyclodextrin in the development of antimicrobial nanosystems.Methods: The nanosystems were prepared by kneading and solubilization followed by freeze-drying technique. The nanosystems were characterized by X-ray powder diffraction (XRPD, differential scanning calorimetry (DSC, and Fourier transform infrared spectroscopy (FTIR. Nanosystem antimicrobial activity against Streptococcus mutans and Candida albicans strains was evaluated with inhibition halo analysis.Results: The nanocarriers MMTNa and cyclodextrins showed good yields. XRPD, FTIR, and DSC analysis confirmed the proposed nanosystems formation and the suitability of the production methods. The nanosystems that showed best antimicrobial effect were chlorhexidine gluconate (CHX and cyclodextrin inclusion complexes and CHX:MMTNa 60% cation exchange capacity – 24 hours.Conclusion: The nanosystem formulations present higher stability for all chlorhexidine inclusion complexes compared with pure chlorhexidine. The nystatin nanosystems have the potential to mask the

  12. Nisin and its Antimicrobial Effect in Foods

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    Hamparsun Hampikyan

    2007-04-01

    Full Text Available Nisin is a bacteriocin which is produced by Lactococcus lactis and takes its place in I. class bacteriocins which are known as lantibiotics. Nisin has antimicrobial and bactericidal activity against a broad spectrum of gram positive bacteria and spores of Clostridium spp. and Bacillus spp. According to toxicity studies nisin is considered not toxic to humans. Its first established used was as a preservative in processed cheese products and since than numerous other applications in various foods such as meat and meat products, poultry products, sea products and beverages such as beer, wine have been used safely. In this review, the characteristics of nisin, its usage in food and its antimicrobial effect are considered. [TAF Prev Med Bull 2007; 6(2.000: 142-147

  13. Nisin and its Antimicrobial Effect in Foods

    Directory of Open Access Journals (Sweden)

    Hamparsun Hampikyan

    2007-04-01

    Full Text Available Nisin is a bacteriocin which is produced by Lactococcus lactis and takes its place in I. class bacteriocins which are known as lantibiotics. Nisin has antimicrobial and bactericidal activity against a broad spectrum of gram positive bacteria and spores of Clostridium spp. and Bacillus spp. According to toxicity studies nisin is considered not toxic to humans. Its first established used was as a preservative in processed cheese products and since than numerous other applications in various foods such as meat and meat products, poultry products, sea products and beverages such as beer, wine have been used safely. In this review, the characteristics of nisin, its usage in food and its antimicrobial effect are considered. [TAF Prev Med Bull. 2007; 6(2: 142-147

  14. Occurrence of antimicrobial resistance in bacteria from diagnostic samples from dogs

    DEFF Research Database (Denmark)

    Pedersen, Karl; Pedersen, Kristina; Jensen, Helene;

    2007-01-01

    Objectives: To study the occurrence of antimicrobial resistance among common bacterial pathogens from dogs and relate resistance patterns to data on consumption of antimicrobials. Methods: The antimicrobial susceptibility patterns of 201 Staphylococcus intermedius, 37 Streptococcus canis, 39...... Pseudomonas aeruginosa, 25 Pasteurella multocida, 29 Proteus spp. and 449 Escherichia coli isolates from clinical submissions from dogs were determined by a broth-dilution method for determination of minimal inhibitory concentration. Data for consumption of antimicrobials were retrieved from Vet......Stat, a national database for reporting antimicrobial prescriptions. Results: The majority of the antimicrobials prescribed for dogs were broad-spectrum compounds, and extended-spectrum penicillins, cephalosporins and sulphonamides 1 trimethoprim together accounted for 81% of the total amount used for companion...

  15. Differential Actions of Chlorhexidine on the Cell Wall of Bacillus subtilis and Escherichia coli

    OpenAIRE

    Cheung, Hon-Yeung; Wong, Matthew Man-Kin; Cheung, Sau-Ha; Liang, Longman Yimin; Lam, Yun-Wah; Chiu, Sung-Kay

    2012-01-01

    Chlorhexidine is a chlorinated phenolic disinfectant used commonly in mouthwash for its action against bacteria. However, a comparative study of the action of chlorhexidine on the cell morphology of Gram-positive and Gram-negative bacteria is lacking. In this study, the actions of chlorhexidine on the cell morphology were identified with the aids of electron microscopy. After exposure to chlorhexidine, numerous spots of indentation on the cell wall were found in both Bacillus subtilis and Esc...

  16. Cloning of a Cation Efflux Pump Gene Associated with Chlorhexidine Resistance in Klebsiella pneumoniae

    OpenAIRE

    Fang, Chi-Tai; Chen, Haur-Chuan; Chuang, Yi-Ping; Chang, Shan-Chwen; Wang, Jin-Town

    2002-01-01

    Expression libraries of a chlorhexidine-resistant Klebsiella pneumoniae strain were constructed and transformed into Escherichia coli XLOLR. Twenty chlorhexidine-resistant transformants were obtained after selection. All clones contained a novel 903-nucleotide locus. Its sequences were compatible with a cation efflux pump, and the locus was thus designated as cepA. Retransformation using cepA-containing plasmids conferred chlorhexidine resistance to both XLOLR and a chlorhexidine-sensitive K....

  17. Human-Derived Probiotic Lactobacillus reuteri Demonstrate Antimicrobial Activities Targeting Diverse Enteric Bacterial Pathogens

    OpenAIRE

    Spinler, Jennifer K; Taweechotipatr, Malai; Rognerud, Cheryl L.; Ou, Ching N.; Tumwasorn, Somying; Versalovic, James

    2008-01-01

    Lactobacillus reuteri is a commensal-derived anaerobic probiotic that resides in the human gastrointestinal tract. L. reuteri converts glycerol into a potent broad-spectrum antimicrobial compound, reuterin, which inhibits the growth of gram-positive and gram-negative bacteria. In this study, we compared four human-derived L. reuteri isolates (ATCC 55730, ATCC PTA 6475, ATCC PTA 4659, and ATCC PTA 5289) in their ability to produce reuterin and to inhibit the growth of different enteric pathoge...

  18. Antimicrobial activity of the leaf extracts of Hyptis suaveolens (L. poit

    Directory of Open Access Journals (Sweden)

    Mandal S

    2007-01-01

    Full Text Available Steam distillation, petroleum ether, and ethanol extracts from Hyptis suaveolens leaves were evaluated for their antimicrobial activity in vitro . Steam distillation extract exhibited broad-spectrum antibacterial and antifungal activity against the tested organisms. It showed highest antifungal and antibacterial activity against Aspergillus niger and Micrococcus luteus, respectively. Activity indices of A. niger against miconazole (25 µg/ml and M. luteus against chloramphenicol (10 µg/ml were 0.89 and 0.67, respectively.

  19. Molecular Targets of β-Lactam-Based Antimicrobials: Beyond the Usual Suspects

    OpenAIRE

    Konaklieva, Monika I.

    2014-01-01

    The common practice in antibacterial drug development has been to rapidly make an attempt to find ever-more stable and broad-spectrum variants for a particular antibiotic, once a drug resistance for that antibiotic is detected. We are now facing bacterial resistance toward our clinically relevant antibiotics of such a magnitude that the conversation for antimicrobial drug development ought to include effective new antibiotics with alternative mechanisms of action. The electrophilic β-lactam r...

  20. Antimicrobial and cytotoxic effects of phosphoric acid solution compared to other root canal irrigants

    OpenAIRE

    PRADO, Maíra; Emmanuel João Nogueira Leal da SILVA; Thais Mageste DUQUE; ZAIA, Alexandre Augusto; Ferraz, Caio Cezar Randi; de Almeida, José Flávio Affonso; GOMES, Brenda Paula Figueiredo de Almeida

    2015-01-01

    Phosphoric acid has been suggested as an irrigant due to its effectiveness in removing the smear layer. Objectives : The purpose of this study was to compare the antimicrobial and cytotoxic effects of a 37% phosphoric acid solution to other irrigants commonly used in endodontics. Material and Methods : The substances 37% phosphoric acid, 17% EDTA, 10% citric acid, 2% chlorhexidine (solution and gel), and 5.25% NaOCl were evaluated. The antimicrobial activity was tested against Candida albican...

  1. Antimicrobial activity of Eucalyptus globulus oil, xylitol and papain: a pilot study

    OpenAIRE

    Valéria de Siqueira Mota; Ruth Natalia Teresa Turrini; Vanessa de Brito Poveda

    2015-01-01

    OBJECTIVE To evaluate the in vitro antimicrobial activity of the Eucalyptus globulus essential oil, and of the xylitol and papain substances against the following microorganisms: Pseudomonas aeruginosa; Samonella sp.; Staphylococus aureus; Proteus vulgaris; Escherichia coli and Candida albicans. METHOD The in vitro antimicrobial evaluation was used by means of the agar diffusion test and evaluation of the inhibition zone diameter of the tested substances. Chlorhexidine 0.5% was used as contro...

  2. Contact allergy to chlorhexidine in a tertiary dermatology clinic in Denmark

    DEFF Research Database (Denmark)

    Opstrup, Morten S; Johansen, Jeanne D; Zachariae, Claus;

    2016-01-01

    cause the contact allergy, and whether accidental re-exposure occurs in some patients. OBJECTIVES: To estimate the prevalence of chlorhexidine contact allergy in a tertiary dermatology clinic in Denmark; to investigate whether patch testing with both chlorhexidine diacetate and chlorhexidine digluconate...

  3. Comparison of Chlorhexidine and Tincture of Iodine for Skin Antisepsis in Preparation for Blood Sample Collection

    OpenAIRE

    Barenfanger, Joan; Drake, Cheryl; Lawhorn, Jerry; Verhulst, Steven J.

    2004-01-01

    Rates of contamination of blood cultures obtained when skin was prepared with iodine tincture versus chlorhexidine were compared. For iodine tincture, the contamination rate was 2.7%; for chlorhexidine, it was 3.1%. The 0.41% difference is not statistically significant. Chlorhexidine has comparable effectiveness and is safer, cheaper, and preferred by staff, so it is an alternative to iodine tincture.

  4. Chlorhexidine Chip in the Treatment of Chronic Periodontitis – A Clinical Study

    OpenAIRE

    Medaiah, Sangeetha; Srinivas, M; Melath, Anil; Girish, Suragimath; Polepalle, Tejaswin; Dasari, Ankineedu Babu

    2014-01-01

    Aim: The aim of this study was to clinically evaluate the use of biodegradable chlorhexidine chip when used as an adjunct to scaling and root planing (SRP) in the treatment of moderate to severe periodontitis patients. The study also intended to compare the combined therapy (SRP and Chlorhexidine chip) with chlorhexidine chip alone in individuals with periodontitis.

  5. Prevention of intraoperative wound contamination with chlorhexidine shower and scrub.

    Science.gov (United States)

    Garibaldi, R A

    1988-04-01

    In a prospective, controlled, clinical trial, we found that preoperative showering and scrubbing with 4% chlorhexidine gluconate was more effective than povidone-iodine or triclocarban medicated soap in reducing skin colonization at the site of surgical incision. Mean log colony counts of the incision site were one half to one log lower for patients who showered with chlorhexidine compared to those who showered with the other regimens. No growth was observed on 43% of the post shower skin cultures from patients in the chlorhexidine group compared with 16% of the cultures from patients who had povidone-iodine showers and 5% of those from patients who used medicated soap and water. The frequency of positive intraoperative wound cultures was 4% with chlorhexidine, 9% with povidone-iodine and 14% with medicated soap and water. This study demonstrates that chlorhexidine gluconate is a more effective skin disinfectant than either povidone-iodine or triclocarban soap and water and that its use is associated with lower rates of intraoperative wound contamination. PMID:2898503

  6. [Influence of chlorhexidine on the flora of burns].

    Science.gov (United States)

    de Barbeyrac, B; Perro, G; Quentin, C; Cutillas, M; Bebear, C; Sanchez, R

    1985-06-01

    The effect of chlorhexidine baths on surface and in-depth colonization of burns was studied in 12 severely burned patients. 202 swabs and 202 biopsy specimens were cultured. Each patient was sampled before and after a daily chlorhexidine bath on several days. Subsequent to bathing, 41% of swabs became sterile and a 1.41 log10 reduction in the number of germs in biopsy specimens was observed. However, deep flora was unchanged in almost half of cases (43.3%) and was reduced by only 1 to 2 log10 in one-third of cases (35.3%). Chlorhexidine added to baths inhibited surface bacterial growth but had an inconsistent and limited effect on in-depth colonization. PMID:3937137

  7. [The efficacy of three hand asepsis techniques using chlorhexidine gluconate (CHG 2%)].

    Science.gov (United States)

    da Cunha, Érika Rossetto; Matos, Fabiana Gonçalves de Oliveira Azevedo; da Silva, Adriana Maria; de Araújo, Eutália Aparecida Cândido; Ferreira, Karine Azevedo São Leão; Graziano, Kazuko Uchikawa

    2011-12-01

    The scrubbing of hands and forearms using antiseptic agents has been the standard pre-operative procedure to prevent surgical site infection. With the introduction of antiseptic agents, the need to use brushes for pre-operative disinfection has been questioned and it has been recommended that the procedure be abandoned due to the injuries it may cause to the skin. With the purpose to provide the foundations for the efficacy of pre-operative asepsis without using brushes or sponges, the objective of this study was to evaluate three methods of pre-operative asepsis using an antimicrobial agent containing chlorhexidine gluconate - CHG 2%; hand-scrubbing with brush (HSB), hand-scrubbing with sponge (HSS), and hand-rubbing with the antiseptic agent (HRA) only. A comparative crossover study was carried with 29 healthcare providers. Antimicrobial efficacy was measured using the glove-juice method before and after each tested method. Statistical analyses showed there were no significant differences regarding the number of colony-forming units when comparing HRA, HSB, and HSS techniques (p=0.148), which theoretically disregards the need to continue using brushes or sponges for hand asepsis.

  8. Efecto inhibitorio en placa microbiana y propiedades antibacterianas de enjuagatorios de clorhexidina The effects of a chlorhexidine rinses on the development of plaque and antibacterial

    Directory of Open Access Journals (Sweden)

    Ismael Yevenes L

    2003-04-01

    digluconate of chlorhexidine. The effect on 24-h plaque regrowth were measured using of plaque area and plaque index in 3 double-blind studies in 20 subjects. For chlorhexidine concentration studies, sampIes all with different date of elaboration, were employed. The assessment of chlorhexidine was performed by HPLC chromatography. Microbicidal properties were measured by an inhibition assay of development of: Streptococcus mutans, Actinomyces viscosus and Candida albicans. Not significant differences plaque reformed after using the three chlorhexidine mouthwashes but less plaque developed whit the chlorhexidine compared with control. The chlorhexidine concentration were 0.1174%, 0.1168% and 0.091% for A, B and C samples respectively, stability values after 16 months of elaboration respectively. Thus, A and B mouthwashes had normal values of chlorhexidine, while that, for C it would be below its declaimed value. The most dated samples of mouthrinses had microbicidal activity against the tested micro-organisms. The inactivation time of bacterial growth was lesser or equal to 30 seconds. The methodologies applied allow to determine the effectiveness of such mouthrinses with different chlorhexidine concentration, when the results clearly suggests that 0.1 % chlorhexidine is enough to get antiplaque and antimicrobial activity, when used in mouthwashes, not been necessary concentrations more high in the mouthrinses

  9. Fatty acid conjugation enhances the activities of antimicrobial peptides.

    Science.gov (United States)

    Li, Zhining; Yuan, Penghui; Xing, Meng; He, Zhumei; Dong, Chuanfu; Cao, Yongchang; Liu, Qiuyun

    2013-04-01

    Antimicrobial peptides are small molecules that play a crucial role in innate immunity in multi-cellular organisms, and usually expressed and secreted constantly at basal levels to prevent infection, but local production can be augmented upon an infection. The clock is ticking as rising antibiotic abuse has led to the emergence of many drug resistance bacteria. Due to their broad spectrum antibiotic and antifungal activities as well as anti-viral and anti-tumor activities, efforts are being made to develop antimicrobial peptides into future microbial agents. This article describes some of the recent patents on antimicrobial peptides with fatty acid conjugation. Potency and selectivity of antimicrobial peptide can be modulated with fatty acid tails of variable length. Interaction between membranes and antimicrobial peptides was affected by fatty acid conjugation. At concentrations above the critical miscelle concentration (CMC), propensity of solution selfassembly hampered binding of the peptide to cell membranes. Overall, fatty acid conjugation has enhanced the activities of antimicrobial peptides, and occasionally it rendered inactive antimicrobial peptides to be bioactive. Antimicrobial peptides can not only be used as medicine but also as food additives.

  10. The role of antimicrobial peptides in cardiovascular physiology and disease.

    Science.gov (United States)

    Li, Yifeng

    2009-12-18

    Antimicrobial peptides are natural peptide antibiotics, existing ubiquitously in both plant and animal kingdoms. They exhibit broad-spectrum antimicrobial activity and play an important role in host defense against invading microbes. Recently, these peptides have been shown to possess activities unrelated to direct microbial killing and be involved in the complex network of immune responses and inflammation. Thus, their role has now broadened beyond that of endogenous antibiotics. Because of their wide involvement in inflammatory response and the emerging role of inflammation in atherosclerosis, antimicrobial peptides have been proposed to represent an important link between inflammation and the pathogenesis of atherosclerotic cardiovascular diseases. This review highlights recent findings that support a role of these peptides in cardiovascular physiology and disease.

  11. Smart silver nanoparticles: borrowing selectivity from conjugated polymers or antimicrobial peptides

    Directory of Open Access Journals (Sweden)

    Lihong Liu

    2014-06-01

    Full Text Available Silver nanoparticles (AgNPs as novel antimicrobial agents are gaining tremendous exploration in various medical fields due to their broad spectrum activity, efficacy and low cost. The major problem associated with the AgNPs treatment is their narrow therapeutic window. To address this inherent shortcoming, significant efforts have been dedicated to reduce AgNPs cell toxicity and improve their therapeutic index. In this brief review, the emphasis would be placed on development of the combined mechanisms which can enhance the antimicrobial action of AgNPs, arising from investigating the biological differences between microbial and mammalian cells. Using one of our selected antimicrobial cell penetration peptide conjugated AgNPs as an example, we demonstrated that antimicrobial peptides (AMPs anchored AgNPs produced enhanced antimicrobial activities, possibly through multimodal mechanisms including selective binding to microorganisms and producing the intracellularly controlled Ag+ release, thus, improving the therapeutic index of AgNPs.

  12. Antimicrobial activity of magnolol and honokiol against periodontopathic microorganisms.

    Science.gov (United States)

    Chang, B; Lee, Y; Ku, Y; Bae, K; Chung, C

    1998-05-01

    Magnolol (1) and honokiol (2), main compounds from the stem bark of Magnolia obovata Thunb., were evaluated for an antimicrobial activity against periodontopathic microorganisms, Porphyromonas gingivalis, Prevotella gingivalis, Actinobacillus actinomycetemcomitans, Capnocytophaga gingivalis, and Veillonella disper, and a cytotoxicity against human gingival fibroblasts and epithelial cells. Our results indicate that magnolol and honokiol, although less potent than chlorhexidine, show a significant antimicrobial activity against these microorganisms, and a relatively low cytotoxic effect on human gingival cells. Thus, it is suggested that magnolol and honokiol may have a potential therapeutic use as a safe oral antiseptic for the prevention and the treatment of periodontal disease. PMID:9619121

  13. Comparative Evaluation of Propolis, Metronidazole with Chlorhexidine, Calcium Hydroxide and Curcuma Longa Extract as Intracanal Medicament Against E.faecalis– An Invitro Study

    Science.gov (United States)

    Nair, Rashmi; Asrani, Hemant

    2015-01-01

    Introduction The increase of potential side effects and safety concerns of conventional medicaments have led to the recent popularity of herbal alternative medications. The herbal products are known for its high antimicrobial activity, biocompatibility, anti-inflammatory and antioxidant properties. Aim The purpose of this study was to investigate and compare the effectiveness of Propolis, Metronidazole with Chlorhexidine gel, Curcuma Longa and Calcium Hydroxide for elimination of E.faecalis bacteria in extracted teeth samples. Materials and Methods Ninety extracted single rooted intact teeth were taken for the study. Decoronation, removal of apices and chemomechanical preparation was done for all samples. These sterilized samples were then contaminated with pure culture of E.faecalis under laminar flow. The samples were incubated for a period of 21 days. The infected samples were assigned to 5 groups: Group I- Propolis; Group II- Metronidazole with Chlorhexidine gel; Group III- Calcium hydroxide; Group IV- Curcuma Longa; and control group- Saline. Efficacy of newer intracanal medicaments against E.faecalis were carried out in the samples at the end of 1, 2 & 5 days for each group with the help of colorimeter. Student paired t-test, ANOVA and multiple tukey test were used for statistical analysis. Results The value of optical density was statistically significant in all groups when compared to that of control group. Group I (Propolis) produced better antimicrobial efficacy followed by Chlorhexidine Metronidazole combination, Curcuma Longa and Calcium hydroxide. Conclusion Within the limitations of this study, it can be concluded that Propolis showed better antimicrobial properties against E.faecalis than other medicaments. PMID:26673857

  14. Antimicrobial Peptides: Versatile Biological Properties

    Directory of Open Access Journals (Sweden)

    Muthuirulan Pushpanathan

    2013-01-01

    Full Text Available Antimicrobial peptides are diverse group of biologically active molecules with multidimensional properties. In recent past, a wide variety of AMPs with diverse structures have been reported from different sources such as plants, animals, mammals, and microorganisms. The presence of unusual amino acids and structural motifs in AMPs confers unique structural properties to the peptide that attribute for their specific mode of action. The ability of these active AMPs to act as multifunctional effector molecules such as signalling molecule, immune modulators, mitogen, antitumor, and contraceptive agent makes it an interesting candidate to study every aspect of their structural and biological properties for prophylactic and therapeutic applications. In addition, easy cloning and recombinant expression of AMPs in heterologous plant host systems provided a pipeline for production of disease resistant transgenic plants. Besides these properties, AMPs were also used as drug delivery vectors to deliver cell impermeable drugs to cell interior. The present review focuses on the diversity and broad spectrum antimicrobial activity of AMPs along with its multidimensional properties that could be exploited for the application of these bioactive peptides as a potential and promising drug candidate in pharmaceutical industries.

  15. Effect of fluoride and chlorhexidine digluconate mouthrinses on plaque biofilms

    DEFF Research Database (Denmark)

    Rabe, Per; Twetman, Svante; Kinnby, Bertil;

    2015-01-01

    in the pre-molar region were worn by three subjects for 7 days. Control discs were removed before subjects rinsed with 0.1% chlorhexidine digluconate (CHX) or 0.2% sodium fluoride (NaF) for 1 minute. Biofilms were stained with Baclight Live/Dead and z-stacks of images created using confocal scanning laser...

  16. Influence of subinhibitory concentrations of antimicrobials on hydrophobicity, adherence and ultra-structure of Fusobacterium nucleatum

    Directory of Open Access Journals (Sweden)

    Okamoto Ana C.

    2002-01-01

    Full Text Available Fusobacterium nucleatum is considered a bridge organism between earlier and later colonizers in dental biofilms and a putative periodontopathogen. In Dentistry, antimicrobial agents are used for treatment and control of infectious diseases associated with dental plaque. Antiseptics have been used in association with antibiotics to reduce infections after oral surgeries. In this study, the influence of subinhibitory concentrations (SC of chlorhexidine, triclosan, penicillin G and metronidazole, on hydrophobicity, adherence to oral epithelial cells, and ultra-structure of F. nucleatum was examined. All isolates were susceptible to chlorhexidine, triclosan, and metronidazole; however, most of the isolates were susceptible to penicillin G, and all of them were hydrophilic when grown with or without antimicrobials. Adherence was decreased by all antimicrobials. Results suggest that adherence of F. nucleatum was influenced by adhesins because structures such as fimbries or capsule were not observed by transmission electronic microscope.

  17. Broad-spectrum pollination of Plectranthus neochilus

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    C. H. Stirton

    1977-12-01

    Full Text Available The pollination ecology of Plectranthus neochilus Schltr. is discussed and compared with that of another garden plant,  Plectranthus barbatus Andr.. Pollinators and flower visitors of P. neochilus include members of  the Megachilidae, Anthophoridae, Syrphidae, Bombyliidae, Sphingidae, Apidae.

  18. Broad-Spectrum Solution-Processed Photovoltaics

    Science.gov (United States)

    Ip, Alexander Halley

    High global demand for energy coupled with dwindling fossil fuel supply has driven the development of sustainable energy sources such as solar photovoltaics. Emerging solar technologies aim for low-cost, solution-processable materials which would allow wide deployment. Colloidal quantum dots (CQDs) are such a materials system which exhibits the ability to absorb across the entire solar spectrum, including in the infrared where many technologies cannot harvest photons. However, due to their nanocrystalline nature, CQDs are susceptible to surface-associated electronic traps which greatly inhibit performance. In this thesis, surface engineering of CQDs is presented through a combined ligand approach which improves the passivation of surface trap states. A metal halide treatment is found to passivate quantum dot surfaces in solution, while bifunctional organic ligands produce a dense film in solid state. This approach reduced midgap trap states fivefold compared with conventional passivation strategies and led to solar cells with a record certified 7.0% power conversion efficiency. The effect of this process on the electronic structure is studied through photoelectron spectroscopy. It is found that while the halide provides deep trap passivation, the nature of the metal cation on the CQD surface affects the density of band tail states. This effect is explored further through a wide survey of materials, and it is found that the coordination ability of the metal cation is responsible for the suppression of shallow traps. With this understanding of CQD surface passivation, broad spectral usage is then explored through a study of visible-absorbing organolead halide perovskite materials as well as narrow-bandgap CQD solar cells. Control over growth conditions and modification of electrode interfaces resulted in efficient perovskite devices with effective usages of visible photons. For infrared-absorbing CQDs, it is found that, in addition to providing surface trap passivation, ligands must be used to prevent nanocrystal fusion that leads to introduction of band tail states. The most efficient solution-processed infrared solar cells yet reported are achieved through this approach, opening a path towards low-cost photovoltaics with high spectral usage.

  19. Antibacterial effect of triantibiotic mixture, chlorhexidine gel, and two natural materials Propolis and Aloe vera against Enterococcus faecalis: An ex vivo study

    Directory of Open Access Journals (Sweden)

    Leila Bazvand

    2014-01-01

    Full Text Available Background: The aim of this ex vivo study was to compare the antimicrobial effect of triantibiotic paste, 0.2% chlorhexidine gel, Propolis and Aloe vera on Enterococcus faecalis in deep dentin. Materials and Methods: Ninety fresh extracted single-rooted teeth were used in a dentin block model. Seventy-five teeth were infected with E. faecalis and divided into four experimental groups (n = 15. Experimental groups were treated with triantibiotic mixture with distilled water, 0.2% chlorhexidine gel, 70% ethanol + Propolis and Aloe vera. Fifteen teeth treated with distilled water as the positive control and 15 samples, free of bacterial contamination, were considered as the negative control. Gates-Glidden drill #4 was used for removal of surface dentin and Gates-Glidden drill #5 was used to collect samples of deep dentin. The samples were prepared and colony-forming units were counted. Data were analyzed by one-way ANOVA and post hoc Tukey tests. Statistical significance was defined at P 0.05. Aloe vera had antibacterial effects on E. faecalis, but in comparison with other medicaments, it was less effective (P < 0.05. Conclusion: This experimental study showed that triantibiotic mixture, 0.2% chlorhexidine gel, Propolis and Aleo vera were relatively effective against E. faecalis. All the intracanal medicements had similar effects on E. faecalis in deep dentin except for Aloe vera.

  20. Carmellose Mucoadhesive Oral Films Containing Vermiculite/Chlorhexidine Nanocomposites as Innovative Biomaterials for Treatment of Oral Infections

    Directory of Open Access Journals (Sweden)

    Jan Gajdziok

    2015-01-01

    Full Text Available Infectious stomatitis represents the most common oral cavity ailments. Current therapy is insufficiently effective because of the short residence time of topical liquid or semisolid medical formulations. An innovative application form based on bioadhesive polymers featuring prolonged residence time on the oral mucosa may be a solution to this challenge. This formulation consists of a mucoadhesive oral film with incorporated nanocomposite biomaterial that is able to release the drug directly at the target area. This study describes the unique approach of preparing mucoadhesive oral films from carmellose with incorporating a nanotechnologically modified clay mineral intercalated with chlorhexidine. The multivariate data analysis was employed to evaluate the influence of the formulation and process variables on the properties of the medical preparation. This evaluation was complemented by testing the antimicrobial and antimycotic activity of prepared films with the aim of finding the most suitable composition for clinical application. Generally, the best results were obtained with sample containing 20 mg of chlorhexidine diacetate carried by vermiculite, with carmellose in the form of nonwoven textile in its structure. In addition to its promising physicomechanical, chemical, and mucoadhesive properties, the formulation inhibited the growth of Staphylococcus and Candida; the effect was prolonged for tens of hours.

  1. Novel Formulation of Chlorhexidine Spheres and Sustained Release with Multilayered Encapsulation.

    Science.gov (United States)

    Luo, Dong; Shahid, Saroash; Wilson, Rory M; Cattell, Michael J; Sukhorukov, Gleb B

    2016-05-25

    This work demonstrates the synthesis of new chlorhexidine polymorphs with controlled morphology and symmetry, which were used as a template for layer-by-layer (LbL) encapsulation. LbL self-assembly of oppositely charged polyelectrolytes onto the drug surface was used in the current work, as an efficient method to produce a carrier with high drug content, improved drug solubility and sustained release. Coprecipitation of the chlorhexidine polymorphs was performed using chlorhexidine diacetate and calcium chloride solutions. Porous interconnected chlorhexidine spheres were produced by tuning the concentration of calcium chloride. The size of these drug colloids could be further controlled from 5.6 μm to over 20 μm (diameter) by adjusting the coprecipitation temperature. The chlorhexidine content in the spheres was determined to be as high as 90%. These particles were further stabilized by depositing 3.5 bilayers of poly(allylamine hydrochloride) (PAH) and polystyrenesulfonate (PSS) on the surface. In vitro release kinetics of chlorhexidine capsules showed that the multilayer shells could prolong the release, which was further demonstrated by characterizing the remaining chlorhexidine capsules with SEM and confocal microscopy. The new chlorhexidine polymorph and LbL coating has created novel chlorhexidine formulations. Further modification to the chlorhexidine polymorph structure is possible to achieve both sustained and stimuli responsive release, which will enhance its clinical performance in medicine and dentistry. PMID:27176115

  2. DRAMP: a comprehensive data repository of antimicrobial peptides.

    Science.gov (United States)

    Fan, Linlin; Sun, Jian; Zhou, Meifeng; Zhou, Jie; Lao, Xingzhen; Zheng, Heng; Xu, Hanmei

    2016-01-01

    The growing problem of antibiotic-resistant microorganisms results in an urgent need for substitutes to conventional antibiotics with novel modes of action and effective activities. Antimicrobial peptides (AMPs), produced by a wide variety of living organisms acting as a defense mechanism against invading pathogenic microbes, are considered to be such promising alternatives. AMPs display a broad spectrum of antimicrobial activity and a low propensity for developing resistance. Therefore, a thorough understanding of AMPs is essential to exploit them as antimicrobial drugs. Considering this, we developed a comprehensive user-friendly data repository of antimicrobial peptides (DRAMP), which holds 17349 antimicrobial sequences, including 4571 general AMPs, 12704 patented sequences and 74 peptides in drug development. Entries in the database have detailed annotations, especially detailed antimicrobial activity data (shown as target organism with MIC value) and structure information. Annotations also include accession numbers crosslinking to Pubmed, Swiss-prot and Protein Data Bank (PDB). The website of the database comes with easy-to-operate browsing as well as searching with sorting and filtering functionalities. Several useful sequence analysis tools are provided, including similarity search, sequence alignment and conserved domain search (CD-Search). DRAMP should be a useful resource for the development of novel antimicrobial peptide drugs. PMID:27075512

  3. Diversity, Antimicrobial Action and Structure-Activity Relationship of Buffalo Cathelicidins.

    Science.gov (United States)

    Brahma, Biswajit; Patra, Mahesh Chandra; Karri, Satyanagalakshmi; Chopra, Meenu; Mishra, Purusottam; De, Bidhan Chandra; Kumar, Sushil; Mahanty, Sourav; Thakur, Kiran; Poluri, Krishna Mohan; Datta, Tirtha Kumar; De, Sachinandan

    2015-01-01

    Cathelicidins are an ancient class of antimicrobial peptides (AMPs) with broad spectrum bactericidal activities. In this study, we investigated the diversity and biological activity of cathelicidins of buffalo, a species known for its disease resistance. A series of new homologs of cathelicidin4 (CATHL4), which were structurally diverse in their antimicrobial domain, was identified in buffalo. AMPs of newly identified buffalo CATHL4s (buCATHL4s) displayed potent antimicrobial activity against selected Gram positive (G+) and Gram negative (G-) bacteria. These peptides were prompt to disrupt the membrane integrity of bacteria and induced specific changes such as blebing, budding, and pore like structure formation on bacterial membrane. The peptides assumed different secondary structure conformations in aqueous and membrane-mimicking environments. Simulation studies suggested that the amphipathic design of buCATHL4 was crucial for water permeation following membrane disruption. A great diversity, broad-spectrum antimicrobial action, and ability to induce an inflammatory response indicated the pleiotropic role of cathelicidins in innate immunity of buffalo. This study suggests short buffalo cathelicidin peptides with potent bactericidal properties and low cytotoxicity have potential translational applications for the development of novel antibiotics and antimicrobial peptidomimetics.

  4. Diversity, Antimicrobial Action and Structure-Activity Relationship of Buffalo Cathelicidins.

    Directory of Open Access Journals (Sweden)

    Biswajit Brahma

    Full Text Available Cathelicidins are an ancient class of antimicrobial peptides (AMPs with broad spectrum bactericidal activities. In this study, we investigated the diversity and biological activity of cathelicidins of buffalo, a species known for its disease resistance. A series of new homologs of cathelicidin4 (CATHL4, which were structurally diverse in their antimicrobial domain, was identified in buffalo. AMPs of newly identified buffalo CATHL4s (buCATHL4s displayed potent antimicrobial activity against selected Gram positive (G+ and Gram negative (G- bacteria. These peptides were prompt to disrupt the membrane integrity of bacteria and induced specific changes such as blebing, budding, and pore like structure formation on bacterial membrane. The peptides assumed different secondary structure conformations in aqueous and membrane-mimicking environments. Simulation studies suggested that the amphipathic design of buCATHL4 was crucial for water permeation following membrane disruption. A great diversity, broad-spectrum antimicrobial action, and ability to induce an inflammatory response indicated the pleiotropic role of cathelicidins in innate immunity of buffalo. This study suggests short buffalo cathelicidin peptides with potent bactericidal properties and low cytotoxicity have potential translational applications for the development of novel antibiotics and antimicrobial peptidomimetics.

  5. Antimicrobial Pesticides

    Science.gov (United States)

    ... US EPA US Environmental Protection Agency Search Search Pesticides Share Facebook Twitter Google+ Pinterest Contact Us You are here: EPA Home » Pesticides » Antimicrobial Pesticides Antimicrobial Pesticides News and Highlights Disinfection Hierarchy Workshop - October 7 ...

  6. Transcriptomic and biochemical analyses identify a family of chlorhexidine efflux proteins

    OpenAIRE

    Hassan, Karl A.; Jackson, Scott M; Penesyan, Anahit; Patching, Simon G.; Tetu, Sasha G.; Eijkelkamp, Bart A.; Brown, Melissa H.; Henderson, Peter J. F.; Paulsen, Ian T.

    2013-01-01

    Drug resistance is an increasing problem in clinical settings with some bacterial pathogens now resistant to virtually all available drugs. Chlorhexidine is a commonly used antiseptic and disinfectant in hospital environments, and there is increasing resistance to chlorhexidine seen in some pathogenic bacteria, such as Acinetobacter baumannii. This paper examines the global gene expression of A. baumannii in response to chlorhexidine exposure and identifies a gene that we demonstrate to media...

  7. Chlorhexidine Vs. Sterile Vaginal Wash During Labor to Prevent Neonatal Infection

    OpenAIRE

    Nancy L. Eriksen; Keri M. Sweeten; Jorge D. Blanco

    1997-01-01

    Objective: The purpose of this study was to determine if a dilute solution of chlorhexidine used as a one-time vaginal wash intrapartum can reduce the use of postnatal antibiotics and neonatal infection. Methods: Term pregnant women in labor were prospectively randomized to receive either 20 cc of 0.4% chlorhexidine (n = 481) or 20 cc of sterile water (n = 466) placebo. Exclusion criteria included fetal distress, clinical infection, cervical dilatation >6 cm, and known allergy to chlorhexidin...

  8. Antimicrobial and cytotoxic effects of phosphoric acid solution compared to other root canal irrigants

    Directory of Open Access Journals (Sweden)

    Maíra PRADO

    2015-04-01

    Full Text Available Phosphoric acid has been suggested as an irrigant due to its effectiveness in removing the smear layer. Objectives : The purpose of this study was to compare the antimicrobial and cytotoxic effects of a 37% phosphoric acid solution to other irrigants commonly used in endodontics. Material and Methods : The substances 37% phosphoric acid, 17% EDTA, 10% citric acid, 2% chlorhexidine (solution and gel, and 5.25% NaOCl were evaluated. The antimicrobial activity was tested against Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Actinomyces meyeri, Parvimonas micra, Porphyromonas gingivalis, and Prevotella nigrescens according to the agar diffusion method. The cytotoxicity of the irrigants was determined by using the MTT assay. Results : Phosphoric acid presented higher antimicrobial activity compared to the other tested irrigants. With regard to the cell viability, this solution showed results similar to those with 5.25% NaOCl and 2% chlorhexidine (gel and solution, whereas 17% EDTA and 10% citric acid showed higher cell viability compared to other irrigants. Conclusion : Phosphoric acid demonstrated higher antimicrobial activity and cytotoxicity similar to that of 5.25% NaOCl and 2% chlorhexidine (gel and solution.

  9. Chlorhexidine gluconate: to bathe or not to bathe?

    Science.gov (United States)

    Rubin, Caroline; Louthan, Rufina Bavin; Wessels, Erica; McGowan, Mary-Bridgid; Downer, Shantee; Maiden, Jeanne

    2013-01-01

    Despite infection-prevention initiatives, hospital-acquired infections (HAIs) are still a common occurrence. Chlorhexidine gluconate (CHG) is an important antibacterial agent. Research indicates that the intervention of bathing with CHG can reduce the number of HAIs. Chlorhexidine gluconate is known to reduce the bioload of several bacteria, including multiple strains of methicillin-resistant Staphylococcus aureus. Research regarding the intervention of bathing with CHG was assessed and found to reduce central line-related blood stream infections, ventilator-associated pneumonia, and vancomycin-resistant enterococci. The reduction in HAIs was found to be greater as compared to bathing with soap and water. The reduction of these HAIs will allow for a saving of resources, finances and staff time, which may ultimately be passed on to the patient. While further research is indicated, a strong conclusion is drawn that bathing with CHG reduces the number of HAIs. PMID:23470709

  10. A case report of anaphylaxis to chlorhexidine during urinary catheterisation.

    Science.gov (United States)

    Noel, J; Temple, A; Laycock, G J A

    2012-05-01

    Chlorhexidine gluconate is a chemical antiseptic that is effective against Gram positive and negative bacteria and on certain viruses and fungi. A bacteriocidal and bacteriostatic agent, this cationic drug is absorbed on to negatively charged cell surfaces of organisms, disrupting the cell membrane, which results in increased permeability. Its use is mainly topical as a surgical hand antisepsis, site preparation/cleansing and for pre-genitourinary procedures such as urethral catheterisation. Like any drug, caution should be employed with its use as hypersensitivity reactions are being documented increasingly in the medical literature. In the following case, we present a patient who was catheterised with the chlorhexidine containing Instillagel(®) (CliniMed, High Wycombe, UK), prior to undergoing elective orthopaedic surgery.

  11. Chlorhexidine decontamination of sputum for culturing Mycobacterium tuberculosis

    OpenAIRE

    Asmar, Shady; Drancourt, Michel

    2015-01-01

    Background: Culture of Mycobacterium tuberculosis is the gold standard method for the laboratory diagnosis of pulmonary tuberculosis, after effective decontamination. Results: We evaluated squalamine and chlorhexidine to decontaminate sputum specimens for the culture of mycobacteria. Eight sputum specimens were artificially infected with 105 colony-forming units (cfu)/mL Mycobacterium tuberculosis and Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans as contaminants. In the s...

  12. Experimental and Theoretical Investigation of Multispecies Oral Biofilm Resistance to Chlorhexidine Treatment.

    Science.gov (United States)

    Shen, Ya; Zhao, Jia; de la Fuente-Núñez, César; Wang, Zhejun; Hancock, Robert E W; Roberts, Clive R; Ma, Jingzhi; Li, Jun; Haapasalo, Markus; Wang, Qi

    2016-01-01

    We investigate recovery of multispecies oral biofilms following chlorhexidine gluconate (CHX) and CHX with surface modifiers (CHX-Plus) treatment. Specifically, we examine the percentage of viable bacteria in the biofilms following their exposure to CHX and CHX-Plus for 1, 3, and 10 minutes, respectively. Before antimicrobial treatment, the biofilms are allowed to grow for three weeks. We find that (a). CHX-Plus kills bacteria in biofilms more effectively than the regular 2% CHX does, (b). cell continues to be killed for up to one week after exposure to the CHX solutions, (c). the biofilms start to recover after two weeks, the percentage of the viable bacteria recovers in the 1 and 3 minutes treatment groups but not in the 10 minutes treatment group after five weeks, and the biofilms fully return to the pretreatment levels after eight weeks. To understand the mechanism, a mathematical model for multiple bacterial phenotypes is developed, adopting the notion that bacterial persisters exist in the biofilms together with regulatory quorum sensing molecules and growth factor proteins. The model reveals the crucial role played by the persisters, quorum sensing molecules, and growth factors in biofilm recovery, accurately predicting the viable bacterial population after CHX treatment. PMID:27325010

  13. Experimental and Theoretical Investigation of Multispecies Oral Biofilm Resistance to Chlorhexidine Treatment

    Science.gov (United States)

    Shen, Ya; Zhao, Jia; de La Fuente-Núñez, César; Wang, Zhejun; Hancock, Robert E. W.; Roberts, Clive R.; Ma, Jingzhi; Li, Jun; Haapasalo, Markus; Wang, Qi

    2016-06-01

    We investigate recovery of multispecies oral biofilms following chlorhexidine gluconate (CHX) and CHX with surface modifiers (CHX-Plus) treatment. Specifically, we examine the percentage of viable bacteria in the biofilms following their exposure to CHX and CHX-Plus for 1, 3, and 10 minutes, respectively. Before antimicrobial treatment, the biofilms are allowed to grow for three weeks. We find that (a). CHX-Plus kills bacteria in biofilms more effectively than the regular 2% CHX does, (b). cell continues to be killed for up to one week after exposure to the CHX solutions, (c). the biofilms start to recover after two weeks, the percentage of the viable bacteria recovers in the 1 and 3 minutes treatment groups but not in the 10 minutes treatment group after five weeks, and the biofilms fully return to the pretreatment levels after eight weeks. To understand the mechanism, a mathematical model for multiple bacterial phenotypes is developed, adopting the notion that bacterial persisters exist in the biofilms together with regulatory quorum sensing molecules and growth factor proteins. The model reveals the crucial role played by the persisters, quorum sensing molecules, and growth factors in biofilm recovery, accurately predicting the viable bacterial population after CHX treatment.

  14. Comparative evaluation of honey, chlorhexidine gluconate (0.2%) and combination of xylitol and chlorhexidine mouthwash (0.2%) on the clinical level of dental plaque: A 30 days randomized control trial

    OpenAIRE

    Ankita Jain; Dara John Bhaskar; Devanand Gupta; Chandan Agali; Vipul Gupta; Rajendra Kumar Gupta; Priyanka Yadav; Akash B Lavate; Mudita Chaturvedi

    2015-01-01

    Aim: To compare the effect of honey, chlorhexidine mouthwash and combination of xylitol chewing gum and chlorhexidine mouthwash on the dental plaque level. Materials and Methods: Ninety healthy dental students, both male and female, aged between 21 to 25 years participated in the study. The subjects were randomly divided into three groups, i.e. the honey group, the chlorhexidine gluconate mouthwash group and the combination of xylitol chewing gum and chlorhexidine (CHX) mouthwash group. The d...

  15. Recently introduced qacA/B genes in Staphylococcus epidermidis do not increase chlorhexidine MIC/MBC

    DEFF Research Database (Denmark)

    Skovgaard, Sissel; Larsen, Marianne Halberg; Nielsen, Lene Nørby;

    2013-01-01

    Chlorhexidine is used as a disinfectant to prevent surgical infections. Recently, studies have indicated that chlorhexidine usage has selected methicillin-resistant Staphylococcus aureus strains that are tolerant to chlorhexidine and that this may be related to the presence of the qacA/B-encoded ......A/B-encoded efflux pumps. Here, we evaluated if high-level exposure to chlorhexidine selects for tolerant colonizing Staphylococcus epidermidis and we addressed the consequences of long-term exposure to chlorhexidine.......Chlorhexidine is used as a disinfectant to prevent surgical infections. Recently, studies have indicated that chlorhexidine usage has selected methicillin-resistant Staphylococcus aureus strains that are tolerant to chlorhexidine and that this may be related to the presence of the qac...

  16. 严重烧伤患者早期短程应用高效抗生素的研究%Clinical study on the early and short - term use of antibiotics with broad spectrum in severely burned patients

    Institute of Scientific and Technical Information of China (English)

    宗光全; 张茂红; 章冠东; 杜庆安

    2001-01-01

    Objective To investigate the prevention and treatment effects of early and short - term use of antibiotics with broad spectrum on postburn severe infection in severely burned patients . Methods Thirty - five burn patients with TBSA from 50% to 95% were enrolled in the study. The patients were divided into early prevention[ 20 cases, antibiotics were used started from 6 postburn hours (PBH)] and delayed prevention( 15 cases,antibiotics were applied after 48 PBH )groups. Plasma levels of LPS,TNFa and IL -8 were dynamically monitored with the concomitant observation of clinical signs of postburn sepsis.Results After major burns,the plasma levels of LPS,TNFα and IL -8 increased evidently and reached the peak values on 3 ~5 postburn days(PBD). But the levels of all above factors in the early group were obviously lower than those in the delayed group( P < 0. 05 ~0. 01 ). The incidencies of sepsis and internal organ complications within 2 postburn weeks were much lower in the early group than those in the delayed group (P < 0. 05). The subeschar bacterial quantification on 4 ~ 7 PBD was evidently lower in the early group than that in the delayed group ( P < 0. 01 ) . Conclusion Early and short - term use of antibiotics with broad spectrum in severely burned patients could effectively prevent postburn severe infection and lower down the incidence of internal organ complications.%目的探讨早期短程应用高效抗生素对严重烧伤后患者感染的防治效果。方法烧伤患者35例,烧伤面积50%~95%。根据高效抗生素使用时机分为早防组(20例,伤后6 h内开始)和迟防组(15例,伤后48 h开始)。动态检测血浆内毒素( lipopolysaccharide, LPS ) 、肿瘤坏死因子(TNFα)和白细胞介素-8(IL-8)的变化,严密观察脓毒症各项指标。结果大面积烧伤后血LPS、TNFα和IL-8明显升高,于伤后3~5 d达高峰,但早防组明显低于迟防组(P<0.05~0.001)。伤后2周内脓毒症、内

  17. Novel Clostridium difficile Anti-Toxin (TcdA and TcdB) Humanized Monoclonal Antibodies Demonstrate In Vitro Neutralization across a Broad Spectrum of Clinical Strains and In Vivo Potency in a Hamster Spore Challenge Model

    Science.gov (United States)

    Qiu, Hongyu; Cassan, Robyn; Johnstone, Darrell; Han, Xiaobing; Joyee, Antony George; McQuoid, Monica; Masi, Andrea; Merluza, John; Hrehorak, Bryce; Reid, Ross; Kennedy, Kieron; Tighe, Bonnie; Rak, Carla; Leonhardt, Melanie; Dupas, Brian; Saward, Laura; Berry, Jody D.; Nykiforuk, Cory L.

    2016-01-01

    Clostridium difficile (C. difficile) infection (CDI) is the main cause of nosocomial antibiotic-associated colitis and increased incidence of community-associated diarrhea in industrialized countries. At present, the primary treatment of CDI is antibiotic administration, which is effective but often associated with recurrence, especially in the elderly. Pathogenic strains produce enterotoxin, toxin A (TcdA), and cytotoxin, toxin B (TcdB), which are necessary for C. difficile induced diarrhea and gut pathological changes. Administration of anti-toxin antibodies provides an alternative approach to treat CDI, and has shown promising results in preclinical and clinical studies. In the current study, several humanized anti-TcdA and anti-TcdB monoclonal antibodies were generated and their protective potency was characterized in a hamster infection model. The humanized anti-TcdA (CANmAbA4) and anti-TcdB (CANmAbB4 and CANmAbB1) antibodies showed broad spectrum in vitro neutralization of toxins from clinical strains and neutralization in a mouse toxin challenge model. Moreover, co-administration of humanized antibodies (CANmAbA4 and CANmAbB4 cocktail) provided a high level of protection in a dose dependent manner (85% versus 57% survival at day 22 for 50 mg/kg and 20 mg/kg doses, respectively) in a hamster gastrointestinal infection (GI) model. This study describes the protective effects conferred by novel neutralizing anti-toxin monoclonal antibodies against C. difficile toxins and their potential as therapeutic agents in treating CDI. PMID:27336843

  18. 贵州铜仁产广谱抑菌作用细菌素乳酸菌的筛选及鉴定%On the Sift and Identification of the Broad-spectrum Antibacterial Bacteriocin Produced in Tongren, Guizhou

    Institute of Scientific and Technical Information of China (English)

    胡美忠; 张新卓; 刘芸

    2014-01-01

    从贵州铜仁产发酵食品中分离纯化出70余株乳酸菌,采用Agar-spot-test初筛与排除酸、过氧化氢抑制后复筛出一株能产广谱抑菌作用细菌素的乳酸菌(编号G55),经生理生化及16S rDNA鉴定可知G55为植物乳杆菌。抑菌谱实验表明,G55产生的细菌素能抑制革兰阳性菌及革兰阴性菌的生长;蛋白酶实验表明,G55产生的细菌素对胃蛋白酶、蛋白酶K敏感,对胰蛋白酶、α凝乳蛋白酶部分敏感。%More than 70 strains of lactic acid bacteria are separated and purified from the fermented foods made in Tongren, Guizhou. First, they are preliminarily sifted by means of agar-spot-test and then excluded from the inhibition of the acid and hydrogen peroxide. After a second sift, a strain of lactic acid bacteria named G55 which can produce broad-spectrum antibacterial bacteriocin is chosen from them. After the physiobiochemical experiment and the 16SrDNA identification, it is concluded that G55 is an actobacillus plantarum. According to the antibacterial spectrum experiment, it shows that the bacteriocin produced by G55 can inhibit the growth of both gram-positive bacteria and gram-negative bacteria. Meanwhile, the experiment of protease shows that the bacteriorin is sensitive to pepsin and proteinase K and is partially sensitive to trypsin andαcurd protease.

  19. Novel Clostridium difficile Anti-Toxin (TcdA and TcdB Humanized Monoclonal Antibodies Demonstrate In Vitro Neutralization across a Broad Spectrum of Clinical Strains and In Vivo Potency in a Hamster Spore Challenge Model.

    Directory of Open Access Journals (Sweden)

    Hongyu Qiu

    Full Text Available Clostridium difficile (C. difficile infection (CDI is the main cause of nosocomial antibiotic-associated colitis and increased incidence of community-associated diarrhea in industrialized countries. At present, the primary treatment of CDI is antibiotic administration, which is effective but often associated with recurrence, especially in the elderly. Pathogenic strains produce enterotoxin, toxin A (TcdA, and cytotoxin, toxin B (TcdB, which are necessary for C. difficile induced diarrhea and gut pathological changes. Administration of anti-toxin antibodies provides an alternative approach to treat CDI, and has shown promising results in preclinical and clinical studies. In the current study, several humanized anti-TcdA and anti-TcdB monoclonal antibodies were generated and their protective potency was characterized in a hamster infection model. The humanized anti-TcdA (CANmAbA4 and anti-TcdB (CANmAbB4 and CANmAbB1 antibodies showed broad spectrum in vitro neutralization of toxins from clinical strains and neutralization in a mouse toxin challenge model. Moreover, co-administration of humanized antibodies (CANmAbA4 and CANmAbB4 cocktail provided a high level of protection in a dose dependent manner (85% versus 57% survival at day 22 for 50 mg/kg and 20 mg/kg doses, respectively in a hamster gastrointestinal infection (GI model. This study describes the protective effects conferred by novel neutralizing anti-toxin monoclonal antibodies against C. difficile toxins and their potential as therapeutic agents in treating CDI.

  20. Mupirocin and Chlorhexidine Resistance in Staphylococcus aureus in Patients with Community-Onset Skin and Soft Tissue Infections

    OpenAIRE

    Fritz, Stephanie A.; Hogan, Patrick G.; Camins, Bernard C.; Ainsworth, Ali J.; Patrick, Carol; Martin, Madeline S.; Krauss, Melissa J.; Rodriguez, Marcela; Carey-Ann D. Burnham

    2013-01-01

    Decolonization measures, including mupirocin and chlorhexidine, are often prescribed to prevent Staphylococcus aureus skin and soft tissue infections (SSTI). The objective of this study was to determine the prevalence of high-level mupirocin and chlorhexidine resistance in S. aureus strains recovered from patients with SSTI before and after mupirocin and chlorhexidine administration and to determine whether carriage of a mupirocin- or chlorhexidine-resistant strain at baseline precluded S. au...

  1. Differential actions of chlorhexidine on the cell wall of Bacillus subtilis and Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Hon-Yeung Cheung

    Full Text Available Chlorhexidine is a chlorinated phenolic disinfectant used commonly in mouthwash for its action against bacteria. However, a comparative study of the action of chlorhexidine on the cell morphology of gram-positive and gram-negative bacteria is lacking. In this study, the actions of chlorhexidine on the cell morphology were identified with the aids of electron microscopy. After exposure to chlorhexidine, numerous spots of indentation on the cell wall were found in both Bacillus subtilis and Escherichia coli. The number of indentation spots increased with time of incubation and increasing chlorhexidine concentration. Interestingly, the dented spots found in B. subtilis appeared mainly at the hemispherical caps of the cells, while in E. coli the dented spots were found all over the cells. After being exposed to chlorhexidine for a prolonged period, leakage of cellular contents and subsequent ghost cells were observed, especially from B subtilis. By using 2-D gel/MS-MS analysis, five proteins related to purine nucleoside interconversion and metabolism were preferentially induced in the cell wall of E. coli, while three proteins related to stress response and four others in amino acid biosynthesis were up-regulated in the cell wall materials of B. subtilis. The localized morphological damages together with the biochemical and protein analysis of the chlorhexidine-treated cells suggest that chlorhexidine may act on the differentially distributed lipids in the cell membranes/wall of B. subtilis and E. coli.

  2. The danger of chlorhexidine in lignocaine gel: A case report of anaphylaxis during urinary catheterisation

    OpenAIRE

    Stewart, Michael; Lenaghan, Daniel

    2015-01-01

    This article describes a case of anaphylaxis secondary to chlorhexidine during urethral catheterisation. Despite little evidence for the use of antiseptic lubricants in preventing catheter-associated urinary tract infections, the distribution and use of such products continues to be widespread. Chlorhexidine-free lubricating gel is widely available and should be used for urological procedures wherever possible.

  3. Repurposing celecoxib as a topical antimicrobial agent

    Directory of Open Access Journals (Sweden)

    Mohamed N. Seleem

    2015-07-01

    Full Text Available There is an urgent need for new antibiotics and alternative strategies to combat multidrug-resistant bacterial pathogens, which are a growing clinical issue. Repurposing existing approved drugs with known pharmacology and toxicology is an alternative strategy to accelerate antimicrobial research and development. In this study, we show that celecoxib, a marketed inhibitor of cyclooxygenase-2, exhibits broad-spectrum antimicrobial activity against Gram-positive pathogens from a variety of genera, including Staphylococcus, Streptococcus, Listeria, Bacillus, and Mycobacterium, but not against Gram-negative pathogens. However, celecoxib is active against all of the Gram-negative bacteria tested, including strains of, Acinetobacter, and Pseudomonas, when their intrinsic resistance is artificially compromised by outer membrane permeabilizing agents such as colistin. The effect of celecoxib on incorporation of radioactive precursors into macromolecules in Staphylococcus aureus was examined. The primary antimicrobial mechanism of action of celecoxib was the dose-dependent inhibition of RNA, DNA, and protein synthesis. Further, we demonstrate the in vivo efficacy of celecoxib in a methicillin-resistant S. aureus (MRSA infected Caenorhabditis elegans whole animal model. Topical application of celecoxib (1 and 2% significantly reduced the mean bacterial count in a mouse model of MRSA skin infection. Further, celecoxib decreased the levels of all inflammatory cytokines tested, including tumor necrosis factor-α, interleukin-6, interleukin-1 beta, and monocyte chemo attractant protein-1 in wounds caused by MRSA infection. Celecoxib also exhibited synergy with many conventional antimicrobials when tested against four clinical isolates of S. aureus. Collectively, these results demonstrate that celecoxib alone, or in combination with traditional antimicrobials, has a potential to use as a topical drug for the treatment of bacterial skin infections.

  4. Ionically Crosslinked Chitosan Hydrogels for the Controlled Release of Antimicrobial Essential Oils and Metal Ions for Wound Management Applications

    Directory of Open Access Journals (Sweden)

    Wan Li Low

    2016-03-01

    Full Text Available The emerging problems posed by antibiotic resistance complicate the treatment regime required for wound infections and are driving the need to develop more effective methods of wound management. There is growing interest in the use of alternative, broad spectrum, pre-antibiotic antimicrobial agents such as essential oils (e.g., tea tree oil, TTO and metal ions (e.g., silver, Ag+. Both TTO and Ag+ have broad spectrum antimicrobial activity and act on multiple target sites, hence reducing the likelihood of developing resistance. Combining such agents with responsive, controlled release delivery systems such as hydrogels may enhance microbiocidal activity and promote wound healing. The advantages of using chitosan to formulate the hydrogels include its biocompatible, mucoadhesive and controlled release properties. In this study, hydrogels loaded with TTO and Ag+ exhibited antimicrobial activity against P. aeruginosa, S. aureus and C. albicans. Combining TTO and Ag+ into the hydrogel further improved antimicrobial activity by lowering the effective concentrations required, respectively. This has obvious advantages for reducing the potential toxic effects on the healthy tissues surrounding the wound. These studies highlight the feasibility of delivering lower effective concentrations of antimicrobial agents such as TTO and Ag+ in ionically crosslinked chitosan hydrogels to treat common wound-infecting pathogens.

  5. Comparative efficacy of aloe vera mouthwash and chlorhexidine on periodontal health: A randomized controlled trial

    Science.gov (United States)

    Jha, Abhishek; Bhashyam, Mamtha

    2016-01-01

    Background With introduction of many herbal medicines, dentistry has recently evidenced shift of approach for treating many inflammatory oral diseases by using such modalities. Aloe vera is one such product exhibiting multiple benefits and has gained considerable importance in clinical research recently. Aim To compare the efficacy of Aloevera and Chlorhexidine mouthwash on Periodontal Health. Material and Methods Thirty days randomized controlled trial was conducted among 390 dental students. The students were randomized into two intervention groups namely Aloe Vera (AV) chlorhexidine group (CHX) and one control (placebo) group. Plaque index and gingival index was recorded for each participant at baseline, 15 days and 30 days. The findings were than statistically analyzed, ANOVA and Post Hoc test were used. Results There was significant reduction (pAloe Vera (AV) and chlorhexidine group. Post hoc test showed significant difference (paloe Vera and placebo and chlorhexidine and placebo group. No significant difference (pAloe vera, chlorhexidine, dental plaque, gingivitis. PMID:27703614

  6. Pectin gelation with chlorhexidine: Physico-chemical studies in dilute solutions.

    Science.gov (United States)

    Lascol, Manon; Bourgeois, Sandrine; Guillière, Florence; Hangouët, Marie; Raffin, Guy; Marote, Pedro; Lantéri, Pierre; Bordes, Claire

    2016-10-01

    Low methoxyl pectin is known to gel with divalent cations (e.g. Ca(2+), Zn(2+)). In this study, a new way of pectin gelation in the presence of an active pharmaceutical ingredient, chlorhexidine (CX), was highlighted. Thus chlorhexidine interactions with pectin were investigated and compared with the well-known pectin/Ca(2+) binding model. Gelation mechanisms were studied by several physico-chemical methods such as zeta potential, viscosity, size measurements and binding isotherm was determined by Proton Nuclear Magnetic Resonance Spectroscopy ((1)H NMR). The binding process exhibited similar first two steps for both divalent ions: a stoichiometric monocomplexation of the polymer followed by a dimerization step. However, stronger interactions were observed between pectin and chlorhexidine. Moreover, the dimerization step occurred under stoichiometric conditions with chlorhexidine whereas non-stoichiometric conditions were involved with calcium ions. In the case of chlorhexidine, an additional intermolecular binding occurred in a third step. PMID:27312625

  7. Daily Bathing with Chlorhexidine and Its Effects on Nosocomial Infection Rates in Pediatric Oncology Patients.

    Science.gov (United States)

    Raulji, Chittalsinh M; Clay, Kristin; Velasco, Cruz; Yu, Lolie C

    2015-01-01

    Infections remain a serious complication in pediatric oncology patients. To determine if daily bathing with Chlorhexidine gluconate can decrease the rate of nosocomial infection in pediatric oncology patients, we reviewed rates of infections in pediatric oncology patients over a 14-month span. Intervention group received daily bath with Chlorhexidine, while the control group did not receive daily bath. The results showed that daily bath with antiseptic chlorhexidine as daily prophylactic antiseptic topical wash leads to decreased infection density amongst the pediatric oncology patients, especially in patients older than 12 years of age. Furthermore, daily chlorhexidine bathing significantly reduced the rate of hospital acquired infection in patients older than 12 years of age. The findings of this study suggest that daily bathing with chlorhexidine may be an effective measure of reducing nosocomial infection in pediatric oncology patients.

  8. Is there a risk of sensitization and allergy to chlorhexidine in health care workers?

    DEFF Research Database (Denmark)

    Garvey, L H; Roed-Petersen, J; Husum, B

    2003-01-01

    BACKGROUND: In Denmark, chlorhexidine is the standard disinfectant in most hospitals and health care workers are repeatedly exposed to it. The aim of this study was to establish whether there is a risk of sensitization and allergy to chlorhexidine from this type of exposure. METHODS: Two hundred...... and forty-eight doctors, nurses and auxiliary staff were invited to participate in the study. One hundred and four individuals took part in the full study including skin tests and a questionnaire and a further 74 individuals filled in the questionnaire giving a total of 178 questionnaires (72%). Patch tests...... to examine the risk of type I and type IV allergy to chlorhexidine in health care workers with daily exposure to chlorhexidine, we did not identify allergies to chlorhexidine in any of the 104 individuals tested or in the additional 74 individuals who completed the questionnaire. We conclude that an allergy...

  9. Antimicrobial activity of poplar propolis on mutans streptococci and caries development in rats

    OpenAIRE

    ARSLAN, Soley; SİLİCİ, Sibel; PERÇİN, Duygu; Koç, Ayşe Nedret; Er, Özgür

    2012-01-01

    The influence of the different extracts of propolis and chlorhexidine on mutans streptococci and the development of dental caries in rats was examined in this study. Specifically, the antimicrobial effects of propolis extracts (including ethanol, methanol, chloroform, hexane, propylene glycol, and ethyl acetate) on Streptococcus mutans UA159 and Streptococcus sobrinus 6715 were studied. Minimal inhibitory concentration and minimal bactericidal concentration were determined using the National ...

  10. Comparative anti-microbial efficacy of Azadirachta indica irrigant with standard endodontic irrigants: A preliminary study

    OpenAIRE

    Arindam Dutta; Mala Kundabala

    2014-01-01

    Objective: The anti-microbial efficacy of 2.5% sodium hypochlorite (SHC) and 0.2% chlorhexidine gluconate were compared with an experimental irrigant formulated from the Neem tree, Azadirachta indica A. Juss. Materials and Methods: A sample of 36 single rooted anterior teeth with periapical radiolucency and absence of response to vitality tests that required root canal treatment were selected for this study. The test irrigants and their combinations were assigned to five different groups ...

  11. Effect of Fluoride, Chlorhexidine and Fluoride-chlorhexidine Mouthwashes on Salivary Streptococcus mutans Count and the Prevalence of Oral Side Effects

    OpenAIRE

    2015-01-01

    Background and aims. Streptococcus mutans is the main pathogenic agent involved in dental caries, and may be eliminated using mouthwashes. The objective of this study was to compare the effects of fluoride, chlorhexidine, and fluoride-chlorhexidine mouthwashes on salivary S. mutans count after two weeks of use and determine the prevalence of their side effects on the oral mucosa. Materials and methods. In this clinical trial, 120 12-14 year-old students were selected and divided into three gr...

  12. 葡萄球菌肠毒素超抗原广谱抑制性多肽的功能研究%Study on the function of a broad-spectrum inhibitory peptide against SEs superantigen

    Institute of Scientific and Technical Information of China (English)

    王思雄; 李亚斐; 马惠文; 邵江河; 余慧青; 王东林

    2012-01-01

    目的 在前期筛选出针对SEA、SEB、SEC具有广谱抑制性的多肽P72基础上,通过竞争结合实验和动物模型对多肽P72的抑制机制进行探讨.方法 采用竞争结合实验检测多肽P72与MHCⅡ类分子的亲合力;利用“两次攻击(two-hit)法”建立的动物模型研究P72对SEs的体内抑制活性.结果 P72不能与FITC-SEs有效竞争结合Raji细胞上的MHCⅡ类分子,P72对SEA、SEB和SEC致Balb/c小鼠休克效应具有显著的保护作用.结论 P72可能不是与MHCⅡ类分子结合而产生的抑制作用,P72能够在体内抑制SEs的超抗原活性,其具体的抑制机制有待深入研究.%This study aims lo investigate the mechanism of the broad-spectrum inhibitory activity of synthetic peptide P72 against SEA, SEB and SEC based on the previous research of competition assay and animal experiments. We detected the binding ability of the peptide P72 to MHC class Ⅱ molecules by competition assay and assessed the in vivo biological activity of peptide P72 against SEs by the "two-hit animal model. The results indicated that the peptide P72 could not bind to MHC class Ⅱ molecules, while P72 can completely protect most of the Balb/c mice against toxic shock induced by SEA, SEB and SEC. In conclusion, our study demonstrates that the inhibitory activity of peptide P72 may not due lo binding to MHC Ⅱ . And peptide P72 can inhibit the biological activity of SEs in vivo. But the exact mechanism of inhibitory activity of P72 still needs studies.

  13. Comparative effects of chlorhexidine and essential oils containing mouth rinse on stem cells cultured on a titanium surface.

    Science.gov (United States)

    Park, Jun-Beom; Lee, Gil; Yun, Byeong Gon; Kim, Chang-Hyen; Ko, Youngkyung

    2014-04-01

    Chlorhexidine (CHX) and Listerine (LIS), an essential oil compound, are the two commonly used adjunctive agents for mechanical debridement, for reducing the bacterial load in the treatment of peri-implant inflammation. However, antimicrobial agents have been reported to be cytotoxic to the alveolar bone cells and gingival epithelial cells. The present study was performed to examine the effects of antiseptics CHX and LIS, on the morphology and proliferation of stem cells. Stem cells derived from the buccal fat pad were grown on machined titanium discs. Each disc was immersed in CHX or LIS for 30 sec, 1.5 min or 4.5 min. Cell morphology was evaluated with a confocal laser microscope and the viability of the cells was quantitatively analyzed with the cell counting kit-8 (CCK-8). The untreated cells attached to the titanium discs demonstrated well-organized actin cytoskeletons. No marked alterations in the cytoskeletal organization were observed in any of the treated groups. The treatment with CHX and LIS of the titanium discs decreased the viability of the cells grown on the treated discs (P<0.05). The stem cells derived from the buccal fat pad were sensitive to CHX and LIS, and a reduction in cellular viability was observed when these agents were applied to the discs for 30 sec. Further studies are required to determine the optimal application time and concentration of this antimicrobial agent for maximizing the reduction of the bacterial load and minimizing the cytotoxicity to the surrounding cells. PMID:24567172

  14. High Rate of qacA- and qacB-Positive Methicillin-Resistant Staphylococcus aureus Isolates from Chlorhexidine-Impregnated Catheter-Related Bloodstream Infections

    OpenAIRE

    Ho, Cheng-Mao; Li, Chi-Yuan; Ho, Mao-Wang; Lin, Chien-Yu; Liu, Shu-Hui; Lu, Jang-Jih

    2012-01-01

    Chlorhexidine has been widely used for infection control. Although the use of chlorhexidine-impregnated catheters has reduced catheter-related infections, chlorhexidine-resistant Staphylococcus aureus has emerged. The correlation between the existence of the chlorhexidine-resistant genes qacA and qacB (qacA/B) in methicillin-resistant Staphylococcus aureus (MRSA) isolates and the effectiveness of chlorhexidine-impregnated catheters in the prevention of MRSA infections is unknown. Sixty methic...

  15. Effect of three disinfectants (chlorhexidine, sodium hypochlorite and hydrogen peroxide on the microleakage of 7th generation bonding agents

    Directory of Open Access Journals (Sweden)

    Salari Behzad

    2013-10-01

    Full Text Available   Background and Aims : The aim of this study was to evaluate the effect of chlorhexidin 2%, sodium hypochlorite 2.5% and hydrogen peroxide 3% as three effective and regular disinfectants on the microleakage of 7th generation bonding agents in vitro.   Materials and Methods: 45 extracted molar teeth without carries were collected and disinfected. On buccal and lingual aspects of these teeth conventional class V cavity preparation were done (90 cavities, then randomly divided to 4 groups, three of them had 10 teeth (20 cavities and one of them had 5 teeth (10 cavities as control group. Cavities in each experimental group prepared with one of the disinfectants and then 7th generation bonding (Optibond all in one, kerr was used as noted by manufacturer, then cavities filled with composite and polished. Bonding agent was used without our previous disinfectants manipulation in control group. Specimens were thermocycled with 1000 thermal cycles between 5 and 55 0 C each for 30 seconds and then immersed in the methylene blue 5%, then sectioned mesiodistally and investigated for microleakage under stereomicroscope (Olympus, Japan. Data were analyzed using Kruskal-Wallis and Wilcoxon mean rank tests.   Results: Despite the lower mean rank values for the untreated group at both occlusal and gingival aspects, the Kruskal-Wallis procedure (α=0.05 showed that the treatment factor did not significantly affect the mean rank values neither in occlusal (P=0.12 nor in gingival (P=0.39 part of cavities.   Conclusion: According to the results of this study, antimicrobial agents such as chlorhexidine 2%, sodium hypochloride 2.5% and hydrogen peroxide 3% can be used perior to 7th generation dentin bonding agent(Optibond all in one, kerr without much concern.

  16. Synthetic antimicrobial oligomers induce composition-dependent topological transition in membranes

    Science.gov (United States)

    Yang, Lihua; Gordon, Vernita; Mishra, Abhijit; Purdy, Kirstin; Cronan, John; Som, Abhigyan; Tew, Gregory; Wong, Gerard C. L.

    2007-03-01

    Antimicrobial peptides comprise a key component of innate immunity for a wide range of multicellular organisms. Recently, their synthetic analogs have demonstrated broad-spectrum antimicrobial activity via permeating bacterial membranes selectively, although the precise molecular mechanism underlying the activity is still unknown. We systematically investigate interactions and self-assembled structures formed by model bacterial membranes and a prototypical family of phenylene ethynylene-based small molecule antimicrobials with controllable activity and selectivity. Synchrotron small angle x-ray scattering (SAXS) results correlate antibacterial activity and the induced formation of an inverted hexagonal phase, and indicate that the organization of negative curvature lipids such as DOPE are crucially important. Preliminary killing assays of DOPE-deficient mutant bacteria agree with the x-ray results.

  17. Two novel antimicrobial peptides purified from the symbiotic bacteria Xenorhabdus budapestensis NMC-10.

    Science.gov (United States)

    Xiao, Yao; Meng, Fanlu; Qiu, Dewen; Yang, Xiufen

    2012-06-01

    Symbiotic bacteria, which are carried in the intestinal vesicle of the infective stage of juvenile entomopathogenic nematodes, produce broad-spectrum antibiotics. In this study, we aimed to isolate the antimicrobial peptides from the culture of the entomopathogenic bacterium Xenorhabdus budapestensis NMC-10. By screening chromatography columns and optimizing flow rate, pH, salinity and other purification conditions, we identified the final purification procedures which consisted of Q ion-exchange chromatography, gel filtration chromatography and two-step reverse-phase chromatography. Two novel antimicrobial peptides were identified via Q-TOF-TOF and de novo sequencing, and designated as GP-19 and EP-20. Both natural and synthetic peptides demonstrated broad-spectrum antimicrobial activities. The synthetic GP-19 peptide was active against Verticillium dahlia with EC(50) values of 17.54 μg/ml and highly inhibited the growth of a variety of bacteria, while the synthetic EP-20 peptide was highly active against Phytophthora capsici with EC(50) values of 3.14 μg/ml. PMID:22497806

  18. Antimicrobial Activity and Phytochemical Analysis of Morinda tinctoria Roxb. Leaf Extracts

    Institute of Scientific and Technical Information of China (English)

    K Deepti; PUmadevi; GVijayalakshmi; BVinod polarao

    2012-01-01

    Objective: The objective of the present work is to evaluate the presence of Phytochemical constituents and antimicrobial activity of different extracts of leaves of Morinda tinctoria Roxb. Methods: The serial exhaustive extraction was done with a series of solvents: Hexane, Chloroform, Ethylacetate and Methanol with increasing polarity using soxhlet apparatus. The Phytochemical analysis was done by using the standard procedures. Antimicrobial activity was evaluated by Agar well diffusion method against nine human pathogens. Results: The results revealed that the leaf extracts contain a broad spectrum of secondary metabolites: Alkaloids, Phytosterols, Flavonoids, Phenols and Triterpenes in major proportion. Methanol extract was shown to be more effective against all the organisms followed by Ethylacetate, Chloroform and Hexane extracts. Proteus vulgaris (24mm) was found to be most sensitive organism followed by Klebsiella pneumonia (21mm) and Enterococcus feacelis (21mm). Conclusions: The present study concludes that the different extracts of M. tinctoria leaves contain a broad spectrum of secondary metabolites and also exhibit antimicrobial activity against all the tested microorganisms. It can also be concluded that Morinda tinctoria plant can be exploited to discover the bioactive natural products that may serve as leads in the development of new pharmaceuticals.

  19. Further exploration of antimicrobial ketodihydronicotinic acid derivatives by multiple parallel syntheses

    DEFF Research Database (Denmark)

    Laursen, Jane B.; Nielsen, Janne; Haack, T.;

    2006-01-01

    synthetic manner and these were examined in vitro for their antimicrobial potential. Several compounds demonstrated significant broad-spectrum activity against clinically derived bacterial strains but previously known 1-(2,4-difluorophenyl)-6-(4-dimethylaminophenyl)-4-pyridone-3-carboxylic acid (7) remained...... the most potent compound in this class. Cross-resistance with ciprofloxacin supported a commonality of mode of action. Permiabilization of Escherichia coli cells by polymyxin B significantly enhanced potency with these agents suggesting that poor cellular uptake was primarily responsible...

  20. Influence of chlorhexidine digluconate on bond strength durability of a self-etching adhesive system

    Directory of Open Access Journals (Sweden)

    Synara Santos Herênio

    2011-10-01

    Full Text Available Introduction and objective: The aim of this study was to evaluate in vitro the effect of 2% chlorhexidine on bond strength durability of a self-etching adhesive system (ClearFill SE Bond. Material and methods: Forty bovine incisors’ crowns had their labial surfaces abraded to dentinexposure,inorderthatthestandardadhesion dentin exposure, inorderthatthestandardadhesion in order that the standard adhesion area reached 4 mm in diameter. Subsequently, they were divided into four groups, according to the treatments performed on the surfaces and storage time: G1 – adhesive system without chlorhexidine for 24 hours (control group; G2 – adhesive system without chlorhexidine for 6 months (control group; G3 – adhesive system with chlorhexidine for 24 hours (experimental group; G4 – adhesive system with chlorhexidine for 6 months (experimental group. After dentin surface treatments, cylinders of composite resin (Z350 were constructed. Then, the specimens were stored in distilled water according to each group design and storage time. Following, the four groups were subjected to shear bond strength test, at a crosshead speed of 0.5 mm / min. The obtained values were subjected to statistical analysis. Results: The results indicated a significant decrease of bond strength in the group treated with chlorhexidine followed by 24-hour storage when compared to control group. However, there was no significant difference in 6-month storage between the experimental and control groups (p>0.05. Conclusion: The application of 2% chlorhexidine was deleterious for bond strength after 24-hour storage.

  1. Penetration of chlorhexidine coating into tooth enamel: A surface analytical study.

    Science.gov (United States)

    Sodhi, Rana N S; Symington, John

    2016-01-01

    Chlorhexidine has proved an efficient antibacterial agent and has been used successfully to prevent new carious lesions in the teeth of adults and children. The substantivity of chlorhexidine has not been identified with any precision, but is certainly not of short duration. In this work, surface analytical techniques have been applied to study the chemical composition, distribution, and penetration of an applied liquid coating containing chlorhexidine onto tooth enamel in order to ascertain mechanisms by which chlorhexidine keeps its long term substantivity. Several hypotheses have been put forward with regard to its substantivity, including concepts of chlorhexidine remaining as a reservoir upon application either in the epithelial surfaces, the tooth surface, or the biofilm. Alternatively, it has been proposed the teeth themselves act as the reservoir. To study this, a chlorhexidine containing liquid coating was applied to the surface of teeth. These were subsequently transversely cross-sectioned. X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were performed on both surfaces to ascertain chemical composition and distribution of the applied coating. It was found that it formed a coating layer of about 25 μm thick. High spatial ToF-SIMS images showed little evidence of substantial diffusion of chlorhexidine into the enamel, either from the surface or via the enamel lamellae. PMID:27094389

  2. Chlorhexidine-induced elastic and adhesive changes of Escherichia coli cells within a biofilm.

    Science.gov (United States)

    Rodgers, Nicole; Murdaugh, Anne

    2016-01-01

    Chlorhexidine is a widely used, commercially available cationic antiseptic. Although its mechanism of action on planktonic bacteria has been well explored, far fewer studies have examined its interaction with an established biofilm. The physical effects of chlorhexidine on a biofilm are particularly unknown. Here, the authors report the first observations of chlorhexidine-induced elastic and adhesive changes to single cells within a biofilm. The elastic changes are consistent with the proposed mechanism of action of chlorhexidine. Atomic force microscopy and force spectroscopy techniques were used to determine spring constants and adhesion energy of the individual bacteria within an Escherichia coli biofilm. Medically relevant concentrations of chlorhexidine were tested, and cells exposed to 1% (w/v) and 0.1% more than doubled in stiffness, while those exposed to 0.01% showed no change in elasticity. Adhesion to the biofilm also increased with exposure to 1% chlorhexidine, but not for the lower concentrations tested. Given the prevalence of chlorhexidine in clinical and commercial applications, these results have important ramifications on biofilm removal techniques. PMID:27604079

  3. Antimicrobial prophylaxis in minor and major surgery.

    Science.gov (United States)

    Bassetti, M; Righi, E; Astilean, A; Corcione, S; Petrolo, A; Farina, E C; De Rosa, F G

    2015-01-01

    Surgical site infections (SSIs) are a frequent cause of morbidity following surgical procedures. Gram-positive cocci, particularly staphylococci, cause many of these infections, although Gram-negative organisms are also frequently involved. The risk of developing a SSI is associated with a number of factors, including aspects of the operative procedure itself, such as wound classification, and patient-related variables, such as preexisting medical conditions. Antimicrobial prophylaxis (AP) plays an important role in reducing SSIs, especially if patient-related risk factors for SSIs are present. The main components of antimicrobial prophylaxis are: timing, selection of drugs and patients, duration and costs. Compliance with these generally accepted preventive principles may lead to overall decreases in the incidence of these infections. Ideally the administration of the prophylactic agent should start within 30 minutes from the surgical incision. The duration of the AP should not exceed 24 hours for the majority of surgical procedures. The shortest effective period of prophylactic antimicrobial administration is not known and studies have demonstrated that post-surgical antibiotic administration is unnecessary. Furthermore, there were no proven benefits in multiple dose regimens when compared to single-dose regimens. The choice of an appropriate prophylactic antimicrobial agent should be based primarily on efficacy and safety. Broad spectrum antibiotics should be avoided due to the risk of promoting bacterial resistance. Cephalosporins are the most commonly used antibiotics in surgical prophylaxis; specifically, cefazolin or cefuroxime are mainly used in the prophylaxis regimens for cardio-thoracic surgery, vascular surgery, hip or knee arthroplasty surgery, neurosurgical procedures and gynecologic and obstetric procedures. A review of the prophylactic regimens regarding the main surgical procedures is presented. PMID:24561611

  4. Distinct Profiling of Antimicrobial Peptide Families

    KAUST Repository

    Khamis, Abdullah M.

    2014-11-10

    Motivation: The increased prevalence of multi-drug resistant (MDR) pathogens heightens the need to design new antimicrobial agents. Antimicrobial peptides (AMPs) exhibit broad-spectrum potent activity against MDR pathogens and kills rapidly, thus giving rise to AMPs being recognized as a potential substitute for conventional antibiotics. Designing new AMPs using current in-silico approaches is, however, challenging due to the absence of suitable models, large number of design parameters, testing cycles, production time and cost. To date, AMPs have merely been categorized into families according to their primary sequences, structures and functions. The ability to computationally determine the properties that discriminate AMP families from each other could help in exploring the key characteristics of these families and facilitate the in-silico design of synthetic AMPs. Results: Here we studied 14 AMP families and sub-families. We selected a specific description of AMP amino acid sequence and identified compositional and physicochemical properties of amino acids that accurately distinguish each AMP family from all other AMPs with an average sensitivity, specificity and precision of 92.88%, 99.86% and 95.96%, respectively. Many of our identified discriminative properties have been shown to be compositional or functional characteristics of the corresponding AMP family in literature. We suggest that these properties could serve as guides for in-silico methods in design of novel synthetic AMPs. The methodology we developed is generic and has a potential to be applied for characterization of any protein family.

  5. Small molecule interactions with lipid bilayers: a molecular dynamics study of chlorhexidine

    Science.gov (United States)

    van Oosten, Brad; Marquardt, Drew; Sternin, Edward; Harroun, Thad

    2013-03-01

    Chlorhexidine presents an interesting modelling challenge with a hydrophobic hexane connecting two biguanides (arginine analogues) and two aromatic rings. We conducted molecular dynamic simulations using the GROMACS simulation software to reproduce the experimental environment of chlorhexidine in a 1,2-Dimyristoyl-sn-Glycero-3-Phosphocholine (DMPC) bilayer to produce atomic-level information. We constructed an all-atom force field of chlorhexidine from the CHARMM36 force field using well established parameters of certain amino acids. Partial charges were treated differently, which were calculated using GAUSSIAN software. We will compare and contrast the results of our model to that of our neutron scattering experiments previously done in our lab.

  6. Evaluation of the substantivity of chlorhexidine in association with sodium fluoride in vitro

    OpenAIRE

    Freitas Carolina Saliba de; Diniz Henrique França Oliveira; Gomes Jânderson Breder; Sinisterra Rubén Dário; Cortés María Esperanza

    2003-01-01

    The efficacy of the fluoride-chlorhexidine association in the prevention of gingivitis and caries has been advocated for a number of years5,7,14. The objective of the association of these therapeutic agents is a synergistic action. The aim of the present study was to determine the substantivity of chlorhexidine associated or not to sodium fluoride at different intervals of time, in vitro. Bovine enamel surfaces were treated with 0.12% chlorhexidine gluconate (Periogard® - Colgate®) or 0.05% s...

  7. Antimicrobial hydrogels: a new weapon in the arsenal against multidrug-resistant infections.

    Science.gov (United States)

    Ng, Victor W L; Chan, Julian M W; Sardon, Haritz; Ono, Robert J; García, Jeannette M; Yang, Yi Yan; Hedrick, James L

    2014-11-30

    The rapid emergence of antibiotic resistance in pathogenic microbes is becoming an imminent global public health problem. Treatment with conventional antibiotics often leads to resistance development as the majority of these antibiotics act on intracellular targets, leaving the bacterial morphology intact. Thus, they are highly prone to develop resistance through mutation. Much effort has been made to develop macromolecular antimicrobial agents that are less susceptible to resistance as they function by microbial membrane disruption. Antimicrobial hydrogels constitute an important class of macromolecular antimicrobial agents, which have been shown to be effective in preventing and treating multidrug-resistant infections. Advances in synthetic chemistry have made it possible to tailor molecular structure and functionality to impart broad-spectrum antimicrobial activity as well as predictable mechanical and rheological properties. This has significantly broadened the scope of potential applications that range from medical device and implant coating, sterilization, wound dressing, to antimicrobial creams for the prevention and treatment of multidrug-resistant infections. In this review, advances in both chemically and physically cross-linked natural and synthetic hydrogels possessing intrinsic antimicrobial properties or loaded with antibiotics, antimicrobial polymers/peptides and metal nanoparticles are highlighted. Relationships between physicochemical properties and antimicrobial activity/selectivity, and possible antimicrobial mechanisms of the hydrogels are discussed. Approaches to mitigating toxicity of metal nanoparticles that are encapsulated in hydrogels are reviewed. In addition, challenges and future perspectives in the development of safe and effective antimicrobial hydrogel systems especially involving co-delivery of antimicrobial polymers/peptides and conventional antimicrobial agents for eventual clinical applications are presented.

  8. Antimicrobial hydrogels: a new weapon in the arsenal against multidrug-resistant infections.

    Science.gov (United States)

    Ng, Victor W L; Chan, Julian M W; Sardon, Haritz; Ono, Robert J; García, Jeannette M; Yang, Yi Yan; Hedrick, James L

    2014-11-30

    The rapid emergence of antibiotic resistance in pathogenic microbes is becoming an imminent global public health problem. Treatment with conventional antibiotics often leads to resistance development as the majority of these antibiotics act on intracellular targets, leaving the bacterial morphology intact. Thus, they are highly prone to develop resistance through mutation. Much effort has been made to develop macromolecular antimicrobial agents that are less susceptible to resistance as they function by microbial membrane disruption. Antimicrobial hydrogels constitute an important class of macromolecular antimicrobial agents, which have been shown to be effective in preventing and treating multidrug-resistant infections. Advances in synthetic chemistry have made it possible to tailor molecular structure and functionality to impart broad-spectrum antimicrobial activity as well as predictable mechanical and rheological properties. This has significantly broadened the scope of potential applications that range from medical device and implant coating, sterilization, wound dressing, to antimicrobial creams for the prevention and treatment of multidrug-resistant infections. In this review, advances in both chemically and physically cross-linked natural and synthetic hydrogels possessing intrinsic antimicrobial properties or loaded with antibiotics, antimicrobial polymers/peptides and metal nanoparticles are highlighted. Relationships between physicochemical properties and antimicrobial activity/selectivity, and possible antimicrobial mechanisms of the hydrogels are discussed. Approaches to mitigating toxicity of metal nanoparticles that are encapsulated in hydrogels are reviewed. In addition, challenges and future perspectives in the development of safe and effective antimicrobial hydrogel systems especially involving co-delivery of antimicrobial polymers/peptides and conventional antimicrobial agents for eventual clinical applications are presented. PMID:25450263

  9. Synergistic Antibacterial Effects of Nanoparticles Encapsulated with Scutellaria baicalensis and Pure Chlorhexidine on Oral Bacterial Biofilms

    Directory of Open Access Journals (Sweden)

    Ken Cham-Fai Leung

    2016-04-01

    Full Text Available Scutellaria baicalensis (SB is a traditional Chinese medicine for treating infectious and inflammatory diseases. Our recent study shows potent antibacterial effects of nanoparticle-encapsulated chlorhexidine (Nano-CHX. Herein, we explored the synergistic effects of the nanoparticle-encapsulated SB (Nano-SB and Nano-CHX on oral bacterial biofilms. Loading efficiency of Nano-SB was determined by thermogravimetric analysis, and its releasing profile was assessed by high-performance liquid chromatographyusing baicalin (a flavonoid compound of SB as the marker. The mucosal diffusion assay on Nano-SB was undertaken in a porcine model. The antibacterial effects of the mixed nanoparticles (Nano-MIX of Nano-SB and Nano-CHX at 9:1 (w/w ratio were analyzed in both planktonic and biofilm modes of representative oral bacteria. The Nano-MIX was effective on the mono-species biofilms of Streptococcus (S. mutans, S. sobrinus, Fusobacterium (F. nucleatum, and Aggregatibacter (A. actinomycetemcomitans (MIC 50 μg/mL at 24 h, and exhibited an enhanced effect against the multi-species biofilms such as S. mutans, F. nucleatum, A. actinomycetemcomitans, and Porphyromonas (P. gingivalis (MIC 12.5 μg/mL at 24 h that was supported by the findings of both scanning electron microscopy (SEM and confocal scanning laser microscopy (CLSM. This study shows enhanced synergistic antibacterial effects of the Nano-MIX on common oral bacterial biofilms, which could be potentially developed as a novel antimicrobial agent for clinical oral/periodontal care.

  10. Microscopic and spectroscopic analyses of chlorhexidine tolerance in Delftia acidovorans biofilms.

    Science.gov (United States)

    Rema, Tara; Lawrence, John R; Dynes, James J; Hitchcock, Adam P; Korber, Darren R

    2014-10-01

    The physicochemical responses of Delftia acidovorans biofilms exposed to the commonly used antimicrobial chlorhexidine (CHX) were examined in this study. A CHX-sensitive mutant (MIC, 1.0 μg ml(-1)) was derived from a CHX-tolerant (MIC, 15.0 μg ml(-1)) D. acidovorans parent strain using transposon mutagenesis. D. acidovorans mutant (MT51) and wild-type (WT15) strain biofilms were cultivated in flow cells and then treated with CHX at sub-MIC and inhibitory concentrations and examined by confocal laser scanning microscopy (CLSM), scanning transmission X-ray microscopy (STXM), and infrared (IR) spectroscopy. Specific morphological, structural, and chemical compositional differences between the CHX-treated and -untreated biofilms of both strains were observed. Apart from architectural differences, CLSM revealed a negative effect of CHX on biofilm thickness in the CHX-sensitive MT51 biofilms relative to those of the WT15 strain. STXM analyses showed that the WT15 biofilms contained two morphochemical cell variants, whereas only one type was detected in the MT51 biofilms. The cells in the MT51 biofilms bioaccumulated CHX to a similar extent as one of the cell types found in the WT15 biofilms, whereas the other cell type in the WT15 biofilms did not bioaccumulate CHX. STXM and IR spectral analyses revealed that CHX-sensitive MT51 cells accumulated the highest levels of CHX. Pretreating biofilms with EDTA promoted the accumulation of CHX in all cells. Thus, it is suggested that a subpopulation of cells that do not accumulate CHX appear to be responsible for greater CHX resistance in D. acidovorans WT15 biofilm in conjunction with the possible involvement of bacterial membrane stability.

  11. Chlorhexidine substantivity on salivary flora and plaque-like biofilm: an in situ model.

    Directory of Open Access Journals (Sweden)

    Lucía García-Caballero

    Full Text Available OBJECTIVE: To evaluate the in situ antibacterial activity of a mouthrinse with 0.2% Chlorhexidine (M-0.2% CHX on undisturbed de novo plaque-like biofilm (PL-biofilm and on salivary flora up to 7 hours after its application. METHODS: A special acrylic appliance was designed, with 3 inserted glass disks on each buccal side, allowing for PL-biofilm growth. Fifteen healthy volunteers wore the appliance for 48 hours and then performed an M-0.2% CHX; disks were removed at 30 seconds and 1, 3, 5 and 7 hours after the mouth-rinsing. Applying a washout period, saliva samples were collected from each volunteer at 30 seconds and 1, 3, 5 and 7 hours after performing an M-0.2% CHX. The PL-biofilm and saliva samples were analysed by confocal laser scanning and epifluorescence microscopes, respectively. RESULTS: At 30 seconds after M-0.2% CHX, the levels of viable bacteria detected in saliva were significantly lower than those observed in PL-biofilm. The difference in the percentage of live bacteria detected in saliva was significantly higher than that observed in PL-biofilm at 5 and 7 hours after M-0.2% CHX. CONCLUSION: After a single mouthrinse of the 0.2% CHX formulation tested in the present study, the 2-day PL-biofilm presented a significantly higher resistance to this antiseptic in situ than that observed in salivary flora. However, this 0.2% CHX formulation showed a higher substantivity on PL-biofilm than on salivary flora at 5 and 7 hours after mouth-rinsing, which could be related to the slower growth rate of PL-biofilm and the possible reservoir function for antimicrobial agents associated with the undisturbed de novo PL-biofilm.

  12. Chlorhexidine: beta-cyclodextrin inhibits yeast growth by extraction of ergosterol

    Directory of Open Access Journals (Sweden)

    K. I. R. Teixeira

    2012-06-01

    Full Text Available Chlorhexidine (Cx augmented with beta-cyclodextrin (β-cd inclusion compounds, termed Cx:β-cd complexes, have been developed for use as antiseptic agents. The aim of this study was to examine the interactions of Cx:β-cd complexes, prepared at different molecular ratios, with sterol and yeast membranes. The Minimal Inhibitory Concentration (MIC against the yeast Candida albicans (C.a. was determined for each complex; the MICs were found to range from 0.5 to 2 µg/mL. To confirm the MIC data, quantitative analysis of viable cells was performed using trypan blue staining. Mechanistic characterization of the interactions that the Cx:β-cd complexes have with the yeast membrane and assessment of membrane morphology following exposure to Cx:β-cd complexes were performed using Sterol Quantification Method analysis (SQM and scanning electron microscopy (SEM. SQM revealed that sterol extraction increased with increasing β-cd concentrations (1.71 × 10³; 1.4 × 10³; 3.45 × 10³, and 3.74 × 10³ CFU for 1:1, 1:2, 1:3, and 1:4, respectively, likely as a consequence of membrane ergosterol solubilization. SEM images demonstrated that cell membrane damage is a visible and significant mechanism that contributes to the antimicrobial effects of Cx:β-cd complexes. Cell disorganization increased significantly as the proportion of β-cyclodextrin present in the complex increased. Morphology of cells exposed to complexes with 1:3 and 1:4 molar ratios of Cx:β-cd were observed to have large aggregates mixed with yeast remains, representing more membrane disruption than that observed in cells treated with Cx alone. In conclusion, nanoaggregates of Cx:β-cd complexes block yeast growth via ergosterol extraction, permeabilizing the membrane by creating cluster-like structures within the cell membrane, possibly due to high amounts of hydrogen bonding.

  13. Economic impact of Tegaderm chlorhexidine gluconate (CHG) dressing in critically ill patients

    Science.gov (United States)

    Thokala, Praveen; Arrowsmith, Martin; Poku, Edith; Martyn-St James, Marissa; Anderson, Jeff; Foster, Steve; Elliott, Tom; Whitehouse, Tony

    2016-01-01

    Purpose: To estimate the economic impact of a TegadermTM chlorhexidine gluconate (CHG) gel dressing compared with a standard intravenous (i.v.) dressing (defined as non-antimicrobial transparent film dressing), used for insertion site care of short-term central venous and arterial catheters (intravascular catheters) in adult critical care patients using a cost-consequence model populated with data from published sources. Material and Methods: A decision analytical cost-consequence model was developed which assigned each patient with an indwelling intravascular catheter and a standard dressing, a baseline risk of associated dermatitis, local infection at the catheter insertion site and catheter-related bloodstream infections (CRBSI), estimated from published secondary sources. The risks of these events for patients with a Tegaderm CHG were estimated by applying the effectiveness parameters from the clinical review to the baseline risks. Costs were accrued through costs of intervention (i.e. Tegaderm CHG or standard intravenous dressing) and hospital treatment costs depended on whether the patients had local dermatitis, local infection or CRBSI. Total costs were estimated as mean values of 10,000 probabilistic sensitivity analysis (PSA) runs. Results: Tegaderm CHG resulted in an average cost-saving of £77 per patient in an intensive care unit. Tegaderm CHG also has a 98.5% probability of being cost-saving compared to standard i.v. dressings. Conclusions: The analyses suggest that Tegaderm CHG is a cost-saving strategy to reduce CRBSI and the results were robust to sensitivity analyses. PMID:27582899

  14. Efficacy of a chlorhexidine and a chlorhexidine-fluoride varnish mixture to decrease interdental levels of mutans streptococci.

    Science.gov (United States)

    Twetman, S; Petersson, L G

    1997-01-01

    The aim of the present study was to evaluate and compare the efficacy of a chlorhexidine/thymol-containing (CHX) and a chlorhexidine/thymol/fluoride-containing (CHX + F) varnish to decrease interdental levels of mutans streptococci (MS). Eighty-two healthy schoolchildren (11-13 years) with high scores of salivary MS were selected by a screening procedure and randomised into two groups. MS were enumerated at all mesial interdental sites of the first permanent molars with the aid of a modified chair-side technique. The interdental molar and premolar sites were treated with either a 1% CHX varnish (Cervitec) or a 1:1 mixture of the CHX varnish and a fluoride varnish containing 0.1% w/w difluorsilane (Fluor Protector; CHX + F) on two occasions within a 2-week period. The varnishes were applied with a small brush after cleaning with dental floss and drying with air. Follow-up samples from the interdental areas were collected after 1 and 3 months. Both groups exhibited a similar statistically significant (p efficacy in diminishing the cariogenic microbial challenge. Thus, the mixed varnish concept should be further developed and warrants an implementation of clinical studies. PMID:9286519

  15. The comparative effects of 0.12% chlorhexidine and herbal oral rinse on dental plaque-induced gingivitis: A randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Devaki Bhate

    2015-01-01

    Full Text Available Background: Chlorhexidine (CHX is considered as a gold standard of antimicrobial rinses. Various herbal oral rinses are available in the market. However, little is known of its effectiveness. Aim: The aim of this study was to evaluate the clinical changes after the usage of herbal oral rinse and 0.12% CHX. Subjects and Methods: In a randomized clinical trial, 76 patients with dental plaque-induced gingivitis were assigned to Group I (Herbal Oral Rinse - Hiora; and 76 patients with dental plaque-induced gingivitis to Group II (0.12% Chlorhexidine-Peridex; . Gingival index and Plaque index scores were recorded at baseline and 21 days after scaling. Results: Intragroup comparison in both groups showed that plaque index and gingival index scores were statistically significant after 21 days as compared to baseline. Intergroup comparison showed that plaque index scores and gingival index scores were statistically significant in Group II as compared to Group I. Conclusion: When herbal oral rinse was compared to 0.12% CHX, 0.12% CHX mouth rinse effectively reduced the clinical symptoms of plaque-induced gingivitis.

  16. Design of the Prevention of Adult Caries Study (PACS: A randomized clinical trial assessing the effect of a chlorhexidine dental coating for the prevention of adult caries

    Directory of Open Access Journals (Sweden)

    Snyder John J

    2010-10-01

    Full Text Available Abstract Background Dental caries is one of the primary causes of tooth loss among adults. It is estimated to affect a majority of Americans aged 55 and older, with a disproportionately higher burden in disadvantaged populations. Although a number of treatments are currently in use for caries prevention in adults, evidence for their efficacy and effectiveness is limited. Methods/Design The Prevention of Adult Caries Study (PACS is a multicenter, placebo-controlled, double-blind, randomized clinical trial of the efficacy of a chlorhexidine (10% w/v dental coating in preventing adult caries. Participants (n = 983 were recruited from four different dental delivery systems serving four diverse communities, including one American Indian population, and were randomized to receive either chlorhexidine or a placebo treatment. The primary outcome is the net caries increment (including non-cavitated lesions from baseline to 13 months of follow-up. A cost-effectiveness analysis also will be considered. Discussion This new dental treatment, if efficacious and approved for use by the Food and Drug Administration (FDA, would become a new in-office, anti-microbial agent for the prevention of adult caries in the United States. Trial Registration Number NCT00357877

  17. Antimicrobial Polymer

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, William F. (Utica, OH); Wright, Stacy C. (Flint, MI); Taylor, Andrew C. (Ann Arbor, MI)

    2004-09-28

    A polymeric composition having antimicrobial properties and a process for rendering the surface of a substrate antimicrobial are disclosed. The polymeric composition comprises a crosslinked chemical combination of (i) a polymer having amino group-containing side chains along a backbone forming the polymer, (ii) an antimicrobial agent selected from metals, metal alloys, metal salts, metal complexes and mixtures thereof, and (iii) a crosslinking agent containing functional groups capable of reacting with the amino groups. In one example embodiment, the polymer is a polyamide formed from a maleic anhydride or maleic acid ester monomer and alkylamines thereby producing a polyamide having amino substituted alkyl chains on one side of the polyamide backbone; the crosslinking agent is a phosphine having the general formula (A).sub.3 P wherein A is hydroxyalkyl; and the metallic antimicrobial agent is selected from chelated silver ions, silver metal, chelated copper ions, copper metal, chelated zinc ions, zinc metal and mixtures thereof.

  18. Antimicrobial potentials of some plant species of the Bignoniaceae family.

    Science.gov (United States)

    Binutu, O A; Lajubutu, B A

    1994-09-01

    The methanol extracts of the leaves and stem bark of four Bignoniaceae plants Jacaranda mimosifolia D. Dol., Tecoma stans Linn., Tabebuia rosea (Bertol) D.C., and Crescentia cujete Linn. were studied for their antimicrobial activity using a wide range of Gram-positive and Gram-negative bacteria and fungi. Extracts of both the leaves and stem bark of majority of plant species studied showed variable but remarkable broad spectrum antimicrobial activity. However, methanol extracts of Tecoma stans leaves was found to be effective against only Candida albicans at the concentrations employed. It was observed that the extracts of stem bark generally showed better antimicrobial activity than those of the leaves and some organisms were selectively more sensitive to the extracts than others. Preliminary phytochemical screening of these plants revealed the presence of tannins, flavonoids, alkaloids, quinones and traces of saponins. The antimicrobial activity observed are discussed in relation to the chemical constituents reportedly isolated from these plants and their traditional uses. PMID:7604753

  19. Production and characterization of antimicrobial active substance from Spirulina platensis.

    Directory of Open Access Journals (Sweden)

    Mostafa M El-Sheekh

    2014-04-01

    Full Text Available The present work was carried out to investigate the ability of Spirulina platensis to produce antimicrobial substance against bacteria and fungi.The cells of the cyanobacterium were subjected to different extractions and the purified antagonistic compound proved to be effective against broad spectrum of bacteria and fungi. The antagonistic compound was purified using thin layer chromatography.The results indicated that the IR spectrum showed bands at 1269 cm(-1, 1414 cm(-1 (C-O-C, 1643 cm(-1 (CO of amide,1563 cm(-1 (C = C and broad band 3441 cm(-1 (of OH and NH., (1HNMR showed δ 0.8 (-CH3, δ 1.2 (-CH2, δ 4.2(-OH, δ 7.2(-NH, δ 7.4 and δ 7.7 (aromatic CH., Mass spectrum showed molecular ion beak at m/z = 341 (abundance (0.03%. Also, the elemental analysis gave molecular formula,C15H18NO8.The purified antimicrobial compound produced by S. platensis was more active against Gram positive, Gram negative bacteria and unicellular fungi, C. albicans. The highest biological activity was recorded against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Aspergillus niger. The results of this investigation proved that cyanobacteria could be a good source for production of antimicrobial agents which could be effective when compared with contemporary antimicrobial compounds.

  20. Epithelial Antimicrobial Peptides: Guardian of the Oral Cavity

    Directory of Open Access Journals (Sweden)

    Mayank Hans

    2014-01-01

    Full Text Available Gingival epithelium provides first line of defence from the microorganisms present in dental plaque. It not only provides a mechanical barrier but also has an active immune function too. Gingival epithelial cells participate in innate immunity by producing a range of antimicrobial peptides to protect the host against oral pathogens. These epithelial antimicrobial peptides (EAPs include the β-defensin family, cathelicidin (LL-37, calprotectin, and adrenomedullin. While some are constitutively expressed in gingival epithelial cells, others are induced upon exposure to microbial insults. It is likely that these EAPs have a role in determining the initiation and progression of oral diseases. EAPs are broad spectrum antimicrobials with a different but overlapping range of activity. Apart from antimicrobial activity, they participate in several other crucial roles in host tissues. Some of these, for instance, β-defensins, are chemotactic to immune cells. Others, such as calprotectin are important for wound healing and cell proliferation. Adrenomedullin, a multifunctional peptide, has its biological action in a wide range of tissues. Not only is it a potent vasodilator but also it has several endocrine effects. Knowing in detail the various bioactions of these EAPs may provide us with useful information regarding their utility as therapeutic agents.

  1. Characterization and performance of short cationic antimicrobial peptide isomers.

    Science.gov (United States)

    Juba, Melanie; Porter, Devin; Dean, Scott; Gillmor, Susan; Bishop, Barney

    2013-07-01

    Cationic antimicrobial peptides (CAMPs) represent an ancient defense mechanism against invading bacteria, with peptides such as the cathelicidins being essential elements of vertebrate innate immunity. CAMPs are typically associated with broad-spectrum antimicrobial potency and limited bacterial resistance. The cathelicidin identified from the elapid snake Naja atra (NA-CATH) contains a semi-conserved repeated 11-residue motif (ATRA motif) with a sequence pattern consistent with formation of an amphipathic helical conformation. Short peptide amides (ATRA-1, -1A, -1P, and -2) generated based on the pair of ATRA motifs in NA-CATH exhibited varied antimicrobial potencies. The small size of the ATRA peptides, coupled with their varied antimicrobial performances, make them interesting models to study the impact various physico-chemical properties have on antimicrobial performance in helical CAMPs. Accordingly, the D- and L-enantiomers of the peptide ATRA-1A, which in earlier studies had shown both good antimicrobial performance and strong helical character, were investigated in order to assess the impact peptide stereochemistry has on antimicrobial performance and interaction with chiral membranes. The ATRA-1A isomers exhibit varied potencies against four bacterial strains, and their conformational properties in the presence of mixed zwitterionic/anionic liposomes are influenced by anionic lipid content. These studies reveal subtle differences in the properties of the peptide isomers. Differences are also seen in the abilities of the ATRA-1A isomers to induce liposome fusion/aggregation, bilayer rearrangement and lysing through turbidity studies and fluorescence microscopy. The similarities and differences in the properties of the ATRA-1A isomers could aid in efforts to develop D-peptide-based therapeutics using high-performing L-peptides as templates.

  2. The caries-preventive effect of chlorhexidine varnish in children and adolescents: a systematic review.

    LENUS (Irish Health Repository)

    James, Patrice

    2010-01-01

    Our purpose was to systematically review the literature on the effectiveness of chlorhexidine varnish for preventing dental caries in children and adolescents and to determine its effectiveness compared to fluoride varnish.

  3. The effect of povidone-iodine and chlorhexidine mouth rinses on plaque Streptococcus mutans count in 6- to 12-year-old school children: An in vivo study

    Directory of Open Access Journals (Sweden)

    Neeraja R

    2008-05-01

    Full Text Available Objectives: Treating a carious tooth in children with high caries experience by providing a restoration does not cure the disease. If the unfavorable oral environment that caused the cavity persists so will the disease and more restorations will be required in future. Treating the oral infection by reducing the number of cariogenic microorganisms and establishing a favorable oral environment to promote predominantly remineralization of tooth structure over time will stop the caries process. The present study was conducted: (1 To evaluate the efficacy of povidone-iodine and chlorhexidine mouth rinses on plaque Streptococcus mutans when used as an adjunct to restoration. (2 To compare the anti-microbial effect of 1% povidone-iodine and 0.2% chlorhexidine mouth rinses on plaque S. mutans count. Study Design: Forty-five study participants in the age group of 6-12 years with dmft (decay component of three or four were selected from one government school in Bangalore city. They were divided into three groups after the restorative treatment. Group-A, Group-B, and Group-C received 1% povidone-iodine mouth rinse, 0.2% chlorhexidine mouth rinse and placebo mouth rinse, respectively, twice daily for 14 days. The plaque sample was collected and S. mutans count was estimated at six phases: (1 Baseline, (2 3 weeks after restoration, (3 First day after mouth rinse therapy, (4 15 days after mouth rinse therapy, (5 1 month and (6 3 months after mouth rinse therapy Results: After the restoration the percentage change in S. mutans count was 28.4%. Immediately after mouth rinse therapy there was significant reduction in S. mutans count in all the three groups. After which the count started to increase gradually and after 3 months the bacterial counts in the povidone-iodine group and placebo group were almost near the postrestorative count. Conclusion: Mouth rinses can be used as adjunct to restoration for short duration as temporary measure in reduction of S

  4. New form of administering chlorhexidine for treatment of denture-induced stomatitis

    OpenAIRE

    Ryalat, Soukaina T

    2011-01-01

    Soukaina Ryalat, Rula Darwish, Wala AminDepartment of Oral Surgery, Jordan University, Amman, JordanBackground: The purpose of this study was to evaluate the release of chlorhexidine as an antifungal drug from doped self-cured poly (methyl methacrylate) (PMMA) acrylic resin and the effect of the drug released on the growth of Candida albicans.Methods: Release of chlorhexidine was evaluated using liquid chromatography, and the effect of the drug on the growth of C. albicans was investigated mi...

  5. Effect of ozonated oil and chlorhexidine gel on plaque induced gingivitis: A randomized control clinical trial

    OpenAIRE

    Maya Sanjeev Indurkar; Renu Verma

    2016-01-01

    Background: Several chemotherapeutic agents have been developed to prevent gingivitis and its progression into periodontitis. In this present study, the efficacy of ozonated oil and chlorhexidine gel was assessed and compared on plaque induced gingivitis. Aim: To evaluate the effect of ozonated oil on plaque induced gingivitis and to compare its efficacy with chlorhexidine gel. Materials and Methods: A total of 20 subjects, aged from 18 to 65 years, with plaque-induced gingivitis were selecte...

  6. Comparison of hexachlorophane and chlorhexidine powders in prevention of neonatal infection.

    OpenAIRE

    Alder, V. G.; Burman, D; Simpson, R. A.; Fysh, J; Gillespie, W. A.

    1980-01-01

    The protective effect of treating the skin of newborn infants with powders containing 1% chlorhexidine or 0.33% hexachlorophane was compared. Each was equally effective in preventing colonisation and infection by Staphylococcus aureus. In contrast, the skin became profusely colonised by coagulase-negative staphylococci, irrespective of the powder used. Venous blood concentrations of chlorhexidine were low or undetectable in the few infants whose blood was analysed.

  7. Prevalence of Chlorhexidine-Resistant Methicillin-Resistant Staphylococcus aureus following Prolonged Exposure

    OpenAIRE

    Schlett, Carey D.; Millar, Eugene V.; Crawford, Katrina B.; Cui, Tianyuan; Lanier, Jeffrey B.; Tribble, David R.; Ellis, Michael W.

    2014-01-01

    Chlorhexidine has been increasingly utilized in outpatient settings to control methicillin-resistant Staphylococcus aureus (MRSA) outbreaks and as a component of programs for MRSA decolonization and prevention of skin and soft-tissue infections (SSTIs). The objective of this study was to determine the prevalence of chlorhexidine resistance in clinical and colonizing MRSA isolates obtained in the context of a community-based cluster-randomized controlled trial for SSTI prevention, during which...

  8. Efficacy of chlorhexidine bathing for reducing healthcare associated bloodstream infections: a meta-analysis

    OpenAIRE

    Choi, Eun Young; Park, Dong-Ah; Kim, Hyun Jung; Park, Jinkyeong

    2015-01-01

    Background We performed a meta-analysis of randomized controlled trials (RCTs) to determine if daily bathing with chlorhexidine decreased hospital-acquired BSIs in critically ill patients. Methods We searched the MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases to identify randomized controlled trials that compared daily bathing with chlorhexidine and a control in critically ill patients. Results This meta-analysis included five RCTs. The overall incidence of meas...

  9. Antimicrobial Activity of Catharanthus roseus – A Detailed Study

    Directory of Open Access Journals (Sweden)

    Prajakta J. Patil

    2010-06-01

    Full Text Available Catharanthus roseus (periwinkle is an important medicinal plant for novel pharmaceuticals since most of the bacterial pathogens are developing resistance against many of the currently available anti microbial drugs. Plants have proved to be significant natural resources for effective chemotherapeutic agents and offering a broad spectrum of activity with greater emphasis on preventive action. This study aims to investigate some of the anti microbial properties of this plant. The anticancer properties of Catharanthus roseus has been the major interest in all investigations. The antimicrobial activity has been checked against microorganisms like Pseudomonas aeruginosa NCIM 2036, Salmonella typhimurium NCIM 2501, Staphylococcus aureus NCIM 5021. The findings show that the extracts from the leaves of this plant can be used as prophylactic agent in many of the diseases, which sometime are of the magnitude of an epidemic.

  10. Comparative assessment of Cranberry and Chlorhexidine mouthwash on streptococcal colonization among dental students: A randomized parallel clinical trial

    OpenAIRE

    Khairnar, Mahesh R.; G. N. Karibasappa; Arun S Dodamani; Prashanthkumar Vishwakarma; Naik, Rahul G.; Manjiri A. Deshmukh

    2015-01-01

    Background: Chlorhexidine gluconate mouthwash has earned an eponym of the gold standard against oral infections, but with certain limitations. There is no effective alternative to Chlorhexidine. Cranberry is known to inhibit bacterial adhesion in various systemic infections and acts as a strong antioxidant. However, it is less explored for its dental use. Hence, there is a need to evaluate its effect against oral infections. Aim: The aim was to compare the efficacy of 0.2% Chlorhexidine mouth...

  11. Chlorhexidine resistance in methicillin-resistant Staphylococcus aureus or just an elevated MIC? An in vitro and in vivo assessment.

    OpenAIRE

    Cookson, B D; Bolton, M C; Platt, J H

    1991-01-01

    Chlorhexidine (Hibiscrub; ICI) is generally accepted to be effective as an antiseptic hand wash for methicillin-susceptible Staphylococcus aureus (MSSA), but there is dispute whether the chlorhexidine MIC for methicillin-resistant S. aureus (MRSA) strains is higher than that for MSSA strains and, indeed, whether it is relevant. In addition, the link between resistance to chlorhexidine, gentamicin, and "nucleic acid-binding" compounds (NAB; which code, in particular, for propamidine isethionat...

  12. Effect of chlorhexidine bathing in preventing infections and reducing skin burden and environmental contamination: A review of the literature.

    Science.gov (United States)

    Donskey, Curtis J; Deshpande, Abhishek

    2016-05-01

    Chlorhexidine bathing is effective in reducing levels of pathogens on skin. In this review, we examine the evidence that chlorhexidine bathing can prevent colonization and infection with health care-associated pathogens and reduce dissemination to the environment and the hands of personnel. The importance of education and monitoring of compliance with bathing procedures is emphasized in order to optimize chlorhexidine bathing in clinical practice. PMID:27131130

  13. Effect of chlorhexidine bathing in preventing infections and reducing skin burden and environmental contamination: A review of the literature.

    Science.gov (United States)

    Donskey, Curtis J; Deshpande, Abhishek

    2016-05-01

    Chlorhexidine bathing is effective in reducing levels of pathogens on skin. In this review, we examine the evidence that chlorhexidine bathing can prevent colonization and infection with health care-associated pathogens and reduce dissemination to the environment and the hands of personnel. The importance of education and monitoring of compliance with bathing procedures is emphasized in order to optimize chlorhexidine bathing in clinical practice.

  14. Antimicrobial Use-Related Problems and Predictors among Hospitalized Medical In-Patients in Southwest Ethiopia: Prospective Observational Study

    Science.gov (United States)

    Yadesa, Tadele Mekuriya; Gudina, Esayas Kebede; Angamo, Mulugeta Tarekegn

    2015-01-01

    Background The spread of antimicrobial resistance in developing countries is associated with complex and interconnected factors, such as excessive and unnecessary prescribing of antimicrobials, increased self-prescribing by the people and poor quality of available antimicrobials. Moreover, the failure to implement infection control practices and the dearth of routine susceptibility testing and surveillance magnify the problems. This may spread the inappropriateness of prescribing, ending up with the spread of antimicrobial resistance. Objective The aim of this study was to assess antimicrobial use related problems and associated factors among patients admitted at Jimma University specialized hospital. Methods A hospital based prospective observational study design was employed at medical wards of Jimma University specialized hospital, Ethiopia. Data collected from patient medication charts and from the patients was analyzed using SPSS, version 16.0. Logistic regression was used to determine the associations between variables. Statistical significance was considered at p-value <0.05. Results Out of 152 study participants, at least one antimicrobial use problem was identified among 115(75.7%). Accordingly, additional antimicrobials were needed by 45(29.6%) of the patients, whereas they were unnecessary among 44(28.9%). Similarly, 17% of the patients were noncompliant to at least one antimicrobial therapy, while 8.6% experienced at least one type of adverse drug reaction. On the other hand, the coverage of the infectious medical condition in the national guidelines (AOR = 4.888) and the duration of hospital stay (AOR = 3.086) were the determinants of the antimicrobial use problems. Conclusion Most of the antimicrobial use problems identified were related to delay of initiation of effective antimicrobials and excessive use; use without indication or using duplicates of broad spectrum antimicrobials or use for longer duration than recommended. The coverage of the

  15. Investigations into the in vitro antimicrobial activity and mode of action of the phenazine antibiotic D-alanylgriseoluteic acid.

    Science.gov (United States)

    Giddens, Stephen R; Bean, David C

    2007-01-01

    D-Alanylgriseoluteic acid (AGA) is a potent antimicrobial phenazine compound produced by Pantoea agglomerans (Erwinia herbicola) Eh1087. Susceptibility tests against a range of microbes indicated that AGA had a broad spectrum of antimicrobial activity and was particularly active against Gram-positive pathogens. Comparison of the in vitro efficacy of AGA with eight other antibiotics against 119 clinical isolates of Streptococcus pneumoniae demonstrated that all were inhibited by low concentrations of AGA (minimal inhibitory concentration range antimicrobials. Investigations into the mode of action of AGA revealed that it induced the SOS response in Escherichia coli and slightly increased the frequency of GC-AT transition mutations. In cell-free assays, both AGA and griseoluteic acid reduced cytochrome c in the presence of a redox recycler (ferredoxin-NADP(+) reductase), but AGA was six to seven times more readily reduced than griseoluteic acid in the absence of the reductase. The potency and broad spectrum of AGA activity suggest that AGA may warrant further investigation. PMID:17189100

  16. Self-assembly of cationic multidomain peptide hydrogels: supramolecular nanostructure and rheological properties dictate antimicrobial activity.

    Science.gov (United States)

    Jiang, Linhai; Xu, Dawei; Sellati, Timothy J; Dong, He

    2015-12-01

    Hydrogels are an important class of biomaterials that have been widely utilized for a variety of biomedical/medical applications. The biological performance of hydrogels, particularly those used as wound dressing could be greatly advanced if imbued with inherent antimicrobial activity capable of staving off colonization of the wound site by opportunistic bacterial pathogens. Possessing such antimicrobial properties would also protect the hydrogel itself from being adversely affected by microbial attachment to its surface. We have previously demonstrated the broad-spectrum antimicrobial activity of supramolecular assemblies of cationic multi-domain peptides (MDPs) in solution. Here, we extend the 1-D soluble supramolecular assembly to 3-D hydrogels to investigate the effect of the supramolecular nanostructure and its rheological properties on the antimicrobial activity of self-assembled hydrogels. Among designed MDPs, the bactericidal activity of peptide hydrogels was found to follow an opposite trend to that in solution. Improved antimicrobial activity of self-assembled peptide hydrogels is dictated by the combined effect of supramolecular surface chemistry and storage modulus of the bulk materials, rather than the ability of individual peptides/peptide assemblies to penetrate bacterial cell membrane as observed in solution. The structure-property-activity relationship developed through this study will provide important guidelines for designing biocompatible peptide hydrogels with built-in antimicrobial activity for various biomedical applications.

  17. A molecular dynamics and circular dichroism study of a novel synthetic antimicrobial peptide

    Science.gov (United States)

    Rodina, N. P.; Yudenko, A. N.; Terterov, I. N.; Eliseev, I. E.

    2013-08-01

    Antimicrobial peptides are a class of small, usually positively charged amphiphilic peptides that are used by the innate immune system to combat bacterial infection in multicellular eukaryotes. Antimicrobial peptides are known for their broad-spectrum antimicrobial activity and thus can be used as a basis for a development of new antibiotics against multidrug-resistant bacteria. The most challengeous task on the way to a therapeutic use of antimicrobial peptides is a rational design of new peptides with enhanced activity and reduced toxicity. Here we report a molecular dynamics and circular dichroism study of a novel synthetic antimicrobial peptide D51. This peptide was earlier designed by Loose et al. using a linguistic model of natural antimicrobial peptides. Molecular dynamics simulation of the peptide folding in explicit solvent shows fast formation of two antiparallel beta strands connected by a beta-turn that is confirmed by circular dichroism measurements. Obtained from simulation amphipatic conformation of the peptide is analysed and possible mechanism of it's interaction with bacterial membranes together with ways to enhance it's antibacterial activity are suggested.

  18. COMPARATIVE ANALYSIS OF ANTIMICROBIAL ACTIVITY OF DIFFERENT VARIETIES OF MURRAYA BY USING MOLECULAR MARKER

    Directory of Open Access Journals (Sweden)

    Dutta Amit Kumar

    2013-06-01

    Full Text Available Murraya koenigii is used as a stimulant, stomachic, febrifuge, analgesic and for treatment of diahrea, dysentery and insect bite. In present study, the antimicrobial activity of different part of Murraya kenigii(leaf, root and barkwas investigated by well diffusion method. As per result, plant extract showed a broad spectrum of very significant antibacterial activity of producing a clear zone of inhibition against, E. coli, Serratia, Klebsiella, Aspergillus niger, Fuesarrium, Penicilium, In this study Murraya is tested for antibacterial and antifungal activity by using Gram positive and Gram negative bacteria and fungi. In the present investigation, all the extract (methanol, ethanol, acetone, petroleum ether were found to be effective against tested pathogenic strains except aqueous extract. Methanol extract showed more pronounced antimicrobial activity than other extracts.

  19. Azurocidin, a natural antibiotic from human neutrophils: expression, antimicrobial activity, and secretion.

    Science.gov (United States)

    Almeida, R P; Vanet, A; Witko-Sarsat, V; Melchior, M; McCabe, D; Gabay, J E

    1996-06-01

    The azurophil granules of human PMN contain four antibiotic proteins, the serprocidins, which have extensive homology to one another and to serine proteases. Azurocidin, a member of this family, is a 29-kDa glycoprotein with broad spectrum antimicrobial activity and chemotactic activity toward monocytes. Insect cells transfected with a baculovirus vector carrying azurocidin cDNA produced a recombinant azurocidin protein. We purified the recombinant azurocidin protein from the culture medium of the infected cells and showed that it retained the antimicrobial activity of the native neutrophil-derived molecule. In addition, we present evidence that a 49-amino-acid region of the recombinant azurocidin protein is required for its secretion from insect cells. PMID:8776752

  20. Molecular Targets of β-Lactam-Based Antimicrobials: Beyond the Usual Suspects

    Directory of Open Access Journals (Sweden)

    Monika I. Konaklieva

    2014-04-01

    Full Text Available The common practice in antibacterial drug development has been to rapidly make an attempt to find ever-more stable and broad-spectrum variants for a particular antibiotic, once a drug resistance for that antibiotic is detected. We are now facing bacterial resistance toward our clinically relevant antibiotics of such a magnitude that the conversation for antimicrobial drug development ought to include effective new antibiotics with alternative mechanisms of action. The electrophilic β-lactam ring is amenable for the inhibition of different enzyme classes by a suitable decoration of the core scaffold. Monocyclic β-lactams lacking an ionizable group at the lactam nitrogen exhibit target preferences toward bacterial enzymes important for resistance and virulence. The present review intends to draw attention to the versatility of the β-lactams as antimicrobials with “unusual” molecular targets.

  1. Stress relaxation analysis facilitates a quantitative approach towards antimicrobial penetration into biofilms.

    Science.gov (United States)

    He, Yan; Peterson, Brandon W; Jongsma, Marije A; Ren, Yijin; Sharma, Prashant K; Busscher, Henk J; van der Mei, Henny C

    2013-01-01

    Biofilm-related infections can develop everywhere in the human body and are rarely cleared by the host immune system. Moreover, biofilms are often tolerant to antimicrobials, due to a combination of inherent properties of bacteria in their adhering, biofilm mode of growth and poor physical penetration of antimicrobials through biofilms. Current understanding of biofilm recalcitrance toward antimicrobial penetration is based on qualitative descriptions of biofilms. Here we hypothesize that stress relaxation of biofilms will relate with antimicrobial penetration. Stress relaxation analysis of single-species oral biofilms grown in vitro identified a fast, intermediate and slow response to an induced deformation, corresponding with outflow of water and extracellular polymeric substances, and bacterial re-arrangement, respectively. Penetration of chlorhexidine into these biofilms increased with increasing relative importance of the slow and decreasing importance of the fast relaxation element. Involvement of slow relaxation elements suggests that biofilm structures allowing extensive bacterial re-arrangement after deformation are more open, allowing better antimicrobial penetration. Involvement of fast relaxation elements suggests that water dilutes the antimicrobial upon penetration to an ineffective concentration in deeper layers of the biofilm. Next, we collected biofilms formed in intra-oral collection devices bonded to the buccal surfaces of the maxillary first molars of human volunteers. Ex situ chlorhexidine penetration into two weeks old in vivo formed biofilms followed a similar dependence on the importance of the fast and slow relaxation elements as observed for in vitro formed biofilms. This study demonstrates that biofilm properties can be derived that quantitatively explain antimicrobial penetration into a biofilm.

  2. Resistance of Antimicrobial Peptide Gene Transgenic Rice to Bacterial Blight

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; WU Chao; LIU Mei; LIU Xu-ri; Hu Guo-cheng; SI Hua-min; SUN Zong-xiu; LIU Wen-zhen; Fu Ya-ping

    2011-01-01

    Antimierobial peptide is a polypeptide with antimicrobial activity.Antimicrobial peptide genes Np3 and Np5 from Chinese shrimp (Fenneropenaeus Chinensis) were integrated into Oryza sativa L.subsp.japonica cv.Aichi ashahi by Agrobacterium mediated transformation system.PCR analysis showed that the positive ratios of Np3 and Np5 were 36% and 45% in T0 generation,respectively.RT-PCR analysis showed that the antimicrobial peptide genes were expressed in T1 generation,and there was no obvious difference in agronomic traits between transgenic plants and non-transgenic plants.Four Np3 and Np5 transgenic lines in T1 generation were inoculated with ×anthomonas oryzae pv.oryzae strain CR4,and all the four transgenic lines had significantly enhanced resistance to bacterial blight caused by the strain CR4.The Np5 transgenic lines also showed higher resistance to bacterial blight caused by strains JS97-2,Zhe 173 and OS-225.It is suggested that transgenic lines with Np5 gene might possess broad spectrum resistance to rice bacterial blight.

  3. Anti-Inflammatory and Antimicrobial activity of Flacourtia Ramontchi Leaves

    Directory of Open Access Journals (Sweden)

    Sulbha Lalsare

    2011-06-01

    Full Text Available The literature survey revealed that a very merge amount of pharmacological work has been carried out on Flacourtia ramontchi. Also it was observed from the Ayurvedic literature and Ethnobotanical studies that the plant is very useful in treating inflammation and infectious diseases but no scientific investigation has been done in such direction. Very merge work has been done regarding phytochemical and pharmacological effectiveness on this plant. Successive extraction of the leaves with solvents of increasing polarity; preliminary phytochemical studies of different extracts; screening of chloroform, methanol and hydromethanolic extracts for anti-inflammatory (by Carrageenan induced rat paw model and antimicrobial activity (by Cup and plate method and thin layer chromatographic studies of active extracts using mobile phase i.e. chloroform and methanol. The results clearly indicate that all three extracts i.e. chloroform, methanol and hydromethanolic, of the leaves having anti-inflammatory activity. But the chloroform and methano extract showed promising results and even chloroform extract at the dose 150mg/kg exhibits equipotent anti-inflammatory activity as that of the standard Indomethacin. Methanol extract possess broad-spectrum antimicrobial activity at concentration 10000 mg/ml whereas hydromethanolic and chloroform extracts having more or less antimicrobial activity.

  4. Avian Antimicrobial Host Defense Peptides: From Biology to Therapeutic Applications

    Directory of Open Access Journals (Sweden)

    Guolong Zhang

    2014-02-01

    Full Text Available Host defense peptides (HDPs are an important first line of defense with antimicrobial and immunomoduatory properties. Because they act on the microbial membranes or host immune cells, HDPs pose a low risk of triggering microbial resistance and therefore, are being actively investigated as a novel class of antimicrobials and vaccine adjuvants. Cathelicidins and β-defensins are two major families of HDPs in avian species. More than a dozen HDPs exist in birds, with the genes in each HDP family clustered in a single chromosomal segment, apparently as a result of gene duplication and diversification. In contrast to their mammalian counterparts that adopt various spatial conformations, mature avian cathelicidins are mostly α-helical. Avian β-defensins, on the other hand, adopt triple-stranded β-sheet structures similar to their mammalian relatives. Besides classical β-defensins, a group of avian-specific β-defensin-related peptides, namely ovodefensins, exist with a different six-cysteine motif. Like their mammalian counterparts, avian cathelicidins and defensins are derived from either myeloid or epithelial origin expressed in a majority of tissues with broad-spectrum antibacterial and immune regulatory activities. Structure-function relationship studies with several avian HDPs have led to identification of the peptide analogs with potential for use as antimicrobials and vaccine adjuvants. Dietary modulation of endogenous HDP synthesis has also emerged as a promising alternative approach to disease control and prevention in chickens.

  5. The Forgotten Role of Alcohol: A Systematic Review and Meta-Analysis of the Clinical Efficacy and Perceived Role of Chlorhexidine in Skin Antisepsis

    OpenAIRE

    Maiwald, Matthias; Chan, Edwin S. Y.

    2012-01-01

    Background Skin antisepsis is a simple and effective measure to prevent infections. The efficacy of chlorhexidine is actively discussed in the literature on skin antisepsis. However, study outcomes due to chlorhexidine-alcohol combinations are often attributed to chlorhexidine alone. Thus, we sought to review the efficacy of chlorhexidine for skin antisepsis and the extent of a possible misinterpretation of evidence. Methods We performed a systematic literature review of clinical trials and s...

  6. Comparative evaluation of honey, chlorhexidine gluconate (0.2% and combination of xylitol and chlorhexidine mouthwash (0.2% on the clinical level of dental plaque: A 30 days randomized control trial

    Directory of Open Access Journals (Sweden)

    Ankita Jain

    2015-01-01

    Full Text Available Aim: To compare the effect of honey, chlorhexidine mouthwash and combination of xylitol chewing gum and chlorhexidine mouthwash on the dental plaque level. Materials and Methods: Ninety healthy dental students, both male and female, aged between 21 to 25 years participated in the study. The subjects were randomly divided into three groups, i.e. the honey group, the chlorhexidine gluconate mouthwash group and the combination of xylitol chewing gum and chlorhexidine (CHX mouthwash group. The data was collected at the baseline, 15 th day and 30 th day; the plaque was disclosed using disclosing solution and their scores were recorded at six sites per tooth using the Quigley and Hein plaque index modified by Turesky-Gilmore-Glickman. Statistical analysis was carried out later to compare the effect of all the three groups. P ≤ 0.05 was considered as statistically significant. Results: Our result showed that all the three groups were effective in reducing the plaque but post-hoc LSD (Least Significant Difference showed that honey group and chlorhexidine + xylitol group were more effective than chlorhexidine group alone. The results demonstrated a significant reduction of plaque indices in honey group and chlorhexidine + xylitol group over a period of 15 and 30 days as compared to chlorhexidine.

  7. Gamma radiation-sterilized, triple-lumen catheters coated with a low concentration of chlorhexidine were not efficacious at preventing catheter infections in intensive care unit patients.

    OpenAIRE

    Sherertz, R J; Heard, S O; Raad, I I; Gentry, L; Bowton, D; Scuderi, P; Hu, J.; Carruth, W; Satishchandra, B; J. Pepe; Mosenthal, A; Burke, T.; Dupuis, J.

    1996-01-01

    In a randomized, double-blind trial, gamma radiation-sterilized, chlorhexidine-coated triple-lumen catheters were compared with uncoated control catheters for their ability to prevent catheter infection in 254 intensive care unit patients. The chlorhexidine coating was not efficacious, and a rabbit model demonstrated that reduction of chlorhexidine activity by gamma radiation sterilization was the likely explanation for the failure.

  8. The effect of 1% chlorhexidine gel and 0.12% dentifrice gel on plaque accumulation: a 3-day non-brushing model

    NARCIS (Netherlands)

    D.E. Slot; N.A.M. Rosema; N.L. Hennequin-Hoenderdos; P.A. Versteeg; U. van der Velden; G.A. van der Weijden

    2010-01-01

    Aim:  The purpose of the study was to compare the effects of four treatments on ‘de novo’ plaque accumulation. Treatments included tray application of 1% chlorhexidine gel (CHX-Gel), 0.12% chlorhexidine dentifrice-gel (CHX-DFG), a regular dentifrice (RDF) tray application, or 0.2% chlorhexidine mout

  9. The effect of chlorhexidine in reducing oral colonisation in geriatric patients: a randomised controlled trial

    Science.gov (United States)

    Sharif-Abdullah, Sharifah Shafinaz Binti; Chong, Mei Chan; Surindar-Kaur, Surat Singh; Kamaruzzaman, Shahrul Bahyah; Ng, Kwan Hoong

    2016-01-01

    INTRODUCTION Inadequate oral care has been implicated in the development of aspiration pneumonia in frail geriatric patients and is a major cause of mortality, due to the colonisation of microbes in vulnerable patients. This type of pneumonia has been associated with an increase in respiratory pathogens in the oral cavity. The aim of this study was to evaluate the effects of chlorhexidine compared to routine oral care in edentulous geriatric inpatients. METHODS A double-blind, parallel-group randomised controlled trial was carried out. The intervention group received oral care with chlorhexidine 0.2%, while the control group received routine oral care with thymol. Nurses provided oral care with assigned solutions of 20 mL once daily over seven days. Oral cavity assessment using the Brief Oral Health Status Examination form was performed before each oral care procedure. Data on medication received and the subsequent development of aspiration pneumonia was recorded. An oral swab was performed on Day 7 to obtain specimens to test for colonisation. RESULTS The final sample consisted of 35 (control) and 43 (intervention) patients. Chlorhexidine was effective in reducing oral colonisation compared to routine oral care with thymol (p < 0.001). The risk of oral bacterial colonisation was nearly three times higher in the thymol group compared to the chlorhexidine group. CONCLUSION The use of chlorhexidine 0.2% significantly reduced oral colonisation and is recommended as an easier and more cost-effective alternative for oral hygiene. PMID:27211885

  10. Efficacy of a probiotic and chlorhexidine mouth rinses: A short-term clinical study

    Directory of Open Access Journals (Sweden)

    Harini P

    2010-09-01

    Full Text Available Introduction: Probiotic technology represents a breakthrough approach to maintaining oral health by utilizing natural beneficial bacteria commonly found in healthy mouths to provide a natural defense against those bacteria thought to be harmful to teeth and gums. However, data are still sparse on the probiotic action in the oral cavity. The review article on probiotics in children published by Twetman and Stecksen- Blicks in 2008 showed only one study of dental interest on probiotics in children. Aim and Objectives: The present study evaluated clinically the efficacy of a probiotic and chlorhexidine mouth rinses on plaque and gingival accumulation in children. The trial design is a double-blind parallel group, 14 days comparative study between a probiotic mouth rinse and a chlorhexidine mouth rinse, which included 45 healthy children in the age group of 6-8 years. Results: The Probiotic and Chlorhexidine groups had less plaque accumulations compared with the Control group at the end of 14 years (P < 0.001 and P < 0.001, respectively. But, unlike the plaque score, there was a significant difference in the Gingival Index between the Probiotic and the Chlorhexidine groups (P = 0.009, Probiotic group being better than the Chlorhexidine group (mean = 0.2300 and 0.6805, respectively. Conclusion: The Probiotic mouth rinse was found effective in reducing plaque accumulation and gingival inflammation. Therefore, probiotic mouth rinse obviously has a potential therapeutic value and further long-term study is recommended to determine its efficacy.

  11. New form of administering chlorhexidine for treatment of denture-induced stomatitis

    Directory of Open Access Journals (Sweden)

    Ryalat S

    2011-06-01

    Full Text Available Soukaina Ryalat, Rula Darwish, Wala AminDepartment of Oral Surgery, Jordan University, Amman, JordanBackground: The purpose of this study was to evaluate the release of chlorhexidine as an antifungal drug from doped self-cured poly (methyl methacrylate (PMMA acrylic resin and the effect of the drug released on the growth of Candida albicans.Methods: Release of chlorhexidine was evaluated using liquid chromatography, and the effect of the drug on the growth of C. albicans was investigated microbiologically using a “well” technique on Saboraud culture medium inoculated with a resistant strain of C. albicans.Results: Chlorhexidine leached steadily out of the acrylic resin into distilled water at mouth temperature, and the sustained drug release continued throughout the 28-day test period. The drug released also demonstrated antifungal activity against the resistant strain of C. albicans.Conclusion: The findings of this study support the use of chlorhexidine-impregnated self-cured PMMA chair-side resin as a new dosage form for the treatment of denture-induced stomatitis.Keywords: chlorhexidine, poly (methyl methacrylate, eluates, antifungal drug, denture stomatitis, Candida albicans

  12. Aspartate Aminotransferase Activity after Gargling with Green Tea and Chlorhexidine Gluconate

    Directory of Open Access Journals (Sweden)

    Christian E. Suryanto

    2013-07-01

    Full Text Available Patients undergoing fixed orthodontic treatment are susceptible to dental plaque accumulation. Plaque can cause inflammation in gingiva. It could be assessed by aspartat aminotransferase (AST in gingival crevicular fluid (GCF. Mouth rinse could be useful to reduce dental plaque accumulation during orthodontic treatment. Chlorhexidine gluconate is often used as mouth rinse in dental practice. On the other hand, green tea is one of natural ingredient that can be used for mouth rinse which is assumed could reduce plaque accumulation. Objectives: To compare the effect between green tea and chlorhexidine gluconate on AST activity in GCF in patient undergoing orthodontic treatment with molar band. Methods: An experimental study was conducted included forty adult subjects. They were randomized into two groups: green tea (n=20 and chlorhexidine gluconate (n=20. AST activity was measured before band insertion, 7 and 30 days after band insertion. One way and two-ways ANOVA were used to analyze the data. Results: The results showed significant difference of AST levels between before, 7 and 30 days after band insertion in the green tea groups (p<0.05. In contrast, there was no significant differences of AST levels between before band insertion, 7 and 30 days after band insertion in the chlorhexidine gluconate groups (p=0.049. There were no difference between each groups with two way ANOVA (p<0.05. Conclusions: Gargle effect of green tea was as effective as chlorhexidine gluconate in reducing AST levels related to banded first molars in adolescents undergoing orthodontic treatment.

  13. Chlorhexidine Digluconate Effects on Planktonic Growth and Biofilm Formation in Some Field Isolates of Animal Bacterial Pathogens

    OpenAIRE

    Ebrahimi, Azizollah; Hemati, Majid; Habibian Dehkordi, Saeed; Bahadoran, Shahab; Khoshnood, Sheida; Khubani, Shahin; Dokht Faraj, Mahdi; Hakimi Alni, Reza

    2014-01-01

    Background: To study chlorhexidine digluconate disinfectant effects on planktonic growth and biofilm formation in some bacterial field isolates from animals. Objectives: The current study investigated chlorhexidine digluconate effects on planktonic growth and biofilm formation in some field isolates of veterinary bacterial pathogens. Materials and Methods: Forty clinical isolates of Escherichia coli, Salmonella serotypes, Staphylococcus. aureus and Streptococcus agalactiae (10 isolates for ea...

  14. Implant decontamination with 2% chlorhexidine during surgical peri-implantitis treatment : a randomized, double-blind, controlled trial

    NARCIS (Netherlands)

    de Waal, Y. C. M.; Raghoebar, G. M.; Meijer, H. J. A.; Winkel, E. G.; van Winkelhoff, A. J.

    2015-01-01

    ObjectiveThe objective of this randomized, double-blind, controlled trial was to evaluate the clinical, radiographic, and microbiological effects of implant surface decontamination with a 2% chlorhexidine (CHX) solution in comparison with a 0.12% chlorhexidine+0.05% cetylpyridinium chloride (CPC) so

  15. Antibacterial kaolinite/urea/chlorhexidine nanocomposites: Experiment and molecular modelling

    International Nuclear Information System (INIS)

    Clay minerals are commonly used materials in pharmaceutical production both as inorganic carriers or active agents. The purpose of this study is the preparation and characterization of clay/antibacterial drug hybrids which can be further included in drug delivery systems for treatment oral infections. Novel nanocomposites with antibacterial properties were successfully prepared by ion exchange reaction from two types of kaolinite/urea intercalates and chlorhexidine diacetate. Intercalation compounds of kaolinite were prepared by reaction with solid urea in the absence of solvents (dry method) as well as with urea aqueous solution (wet method). The antibacterial activity of two prepared samples against Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa was evaluated by finding the minimum inhibitory concentration (MIC). Antibacterial studies of both samples showed the lowest MIC values (0.01%, w/v) after 1 day against E. faecalis, E. coli and S. aureus. A slightly worse antibacterial activity was observed against P. aeruginosa (MIC 0.12%, w/v) after 1 day. Since samples showed very good antibacterial activity, especially after 1 day of action, this means that these samples can be used as long-acting antibacterial materials. Prepared samples were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The experimental data are supported by results of molecular modelling.

  16. Chlorhexidine markedly potentiates the oxidants scavenging abilities of Candida albicans.

    Science.gov (United States)

    Ginsburg, I; Koren, E; Feuerstein, O; Zogakis, I P; Shalish, M; Gorelik, S

    2015-10-01

    The oxidant scavenging ability (OSA) of catalase-rich Candida albicans is markedly enhanced by chlorhexidine digluconate (CHX), polymyxin B, the bile salt ursodeoxycholate and by lysophosphatidylcholine, which all act as detergents facilitating the penetration of oxidants and their intracellular decomposition. Quantifications of the OSA of Candida albicans were measured by a highly sensitive luminol-dependent chemiluminescence assay and by the Thurman's assay, to quantify hydrogen peroxide (H2O2). The OSA enhancing activity by CHX depends to some extent on the media on which candida grew. The OSA of candida treated by CHX was modulated by whole human saliva, red blood cells, lysozyme, cationic peptides and by polyphenols. Concentrations of CHX, which killed over 95 % of Candida albicans cells, did not affect the cells' abilities to scavenge reactive oxygen species (ROS). The OSA of Candida cells treated by CHX is highly refractory to H2O2 (50 mM) but is strongly inhibited by hypochlorous acid, lecithin, trypan blue and by heparin. We speculate that similarly to catalase-rich red blood cells, Candida albicans and additional catalase-rich microbiota may also have the ability to scavenge oxidants and thus can protect catalase-negative anaerobes and facultative anaerobes cariogenic streptococci against peroxide and thus secure their survival in the oral cavity.

  17. Effect of Hydrogen Peroxide on the Antibacterial Substantivity of Chlorhexidine

    Directory of Open Access Journals (Sweden)

    Shahriar Shahriari

    2010-01-01

    Full Text Available The purpose of this in vitro study was to assess the effect of hydrogen peroxide on the antibacterial substantivity of chlorhexidine (CHX. Seventy-five dentine tubes prepared from human maxillary central and lateral incisor teeth were used. After contamination with Enterococcus faecalis for 14 days, the specimens were divided into five groups as follows: CHX, H2O2, CHX + H2O2, infected dentine tubes (positive control, and sterile dentine tubes (negative control. Dentine chips were collected with round burs into tryptic soy broth, and after culturing, the number of colony-forming units (CFU was counted. The number of CFU was minimum in the first cultures in all experimental groups, and the results obtained were significantly different from each other at any time period (<.05. At the first culture, the number of CFU in the CHX + H2O2 group was lower than other two groups. At the other experimental periods, the CHX group showed the most effective antibacterial action (<.05. Hydrogen peroxide group showed the worst result at all periods. In each group, the number of CFU increased significantly by time lapse (<.05. In conclusion, H2O2 had no additive effect on the residual antibacterial activity of CHX.

  18. Antibacterial kaolinite/urea/chlorhexidine nanocomposites: Experiment and molecular modelling

    Energy Technology Data Exchange (ETDEWEB)

    Holešová, Sylva, E-mail: sylva.holesova@vsb.cz [Nanotechnology Centre, VŠB – Technical University of Ostrava, 17.listopadu 15/2172, CZ-708 33 Ostrava, Poruba (Czech Republic); IT4Innovations Centre of Excellence, VŠB – Technical University of Ostrava, 17.listopadu 15/2172, CZ-708 33 Ostrava, Poruba (Czech Republic); Valášková, Marta; Hlaváč, Dominik [Nanotechnology Centre, VŠB – Technical University of Ostrava, 17.listopadu 15/2172, CZ-708 33 Ostrava, Poruba (Czech Republic); IT4Innovations Centre of Excellence, VŠB – Technical University of Ostrava, 17.listopadu 15/2172, CZ-708 33 Ostrava, Poruba (Czech Republic); Madejová, Jana [Institute of Inorganic Chemistry, SAS, Dúbravská cesta 9, SK-845 36 Bratislava (Slovakia); Samlíková, Magda; Tokarský, Jonáš [Nanotechnology Centre, VŠB – Technical University of Ostrava, 17.listopadu 15/2172, CZ-708 33 Ostrava, Poruba (Czech Republic); IT4Innovations Centre of Excellence, VŠB – Technical University of Ostrava, 17.listopadu 15/2172, CZ-708 33 Ostrava, Poruba (Czech Republic); Pazdziora, Erich [Institute of Public Health Ostrava, Centre of Clinical Laboratories, Partyzánské náměstí 7, CZ-702 00 Ostrava (Czech Republic)

    2014-06-01

    Clay minerals are commonly used materials in pharmaceutical production both as inorganic carriers or active agents. The purpose of this study is the preparation and characterization of clay/antibacterial drug hybrids which can be further included in drug delivery systems for treatment oral infections. Novel nanocomposites with antibacterial properties were successfully prepared by ion exchange reaction from two types of kaolinite/urea intercalates and chlorhexidine diacetate. Intercalation compounds of kaolinite were prepared by reaction with solid urea in the absence of solvents (dry method) as well as with urea aqueous solution (wet method). The antibacterial activity of two prepared samples against Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa was evaluated by finding the minimum inhibitory concentration (MIC). Antibacterial studies of both samples showed the lowest MIC values (0.01%, w/v) after 1 day against E. faecalis, E. coli and S. aureus. A slightly worse antibacterial activity was observed against P. aeruginosa (MIC 0.12%, w/v) after 1 day. Since samples showed very good antibacterial activity, especially after 1 day of action, this means that these samples can be used as long-acting antibacterial materials. Prepared samples were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The experimental data are supported by results of molecular modelling.

  19. Antimicrobial resistance

    DEFF Research Database (Denmark)

    Llor, Carl; Bjerrum, Lars

    2014-01-01

    Antimicrobial resistance is a global public health challenge, which has accelerated by the overuse of antibiotics worldwide. Increased antimicrobial resistance is the cause of severe infections, complications, longer hospital stays and increased mortality. Overprescribing of antibiotics...... is associated with an increased risk of adverse effects, more frequent re-attendance and increased medicalization of self-limiting conditions. Antibiotic overprescribing is a particular problem in primary care, where viruses cause most infections. About 90% of all antibiotic prescriptions are issued by general...... practitioners, and respiratory tract infections are the leading reason for prescribing. Multifaceted interventions to reduce overuse of antibiotics have been found to be effective and better than single initiatives. Interventions should encompass the enforcement of the policy of prohibiting the over...

  20. Antimicrobial Peptides

    Directory of Open Access Journals (Sweden)

    Ali Adem Bahar

    2013-11-01

    Full Text Available The rapid increase in drug-resistant infections has presented a serious challenge to antimicrobial therapies. The failure of the most potent antibiotics to kill “superbugs” emphasizes the urgent need to develop other control agents. Here we review the history and new development of antimicrobial peptides (AMPs, a growing class of natural and synthetic peptides with a wide spectrum of targets including viruses, bacteria, fungi, and parasites. We summarize the major types of AMPs, their modes of action, and the common mechanisms of AMP resistance. In addition, we discuss the principles for designing effective AMPs and the potential of using AMPs to control biofilms (multicellular structures of bacteria embedded in extracellular matrixes and persister cells (dormant phenotypic variants of bacterial cells that are highly tolerant to antibiotics.

  1. Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Sigrid Mayrhofer

    2011-01-01

    Full Text Available Strains of the genus Bifidobacterium are frequently used as probiotics, for which the absence of acquired antimicrobial resistance has become an important safety criterion. This clarifies the need for antibiotic susceptibility data for bifidobacteria. Based on a recently published standard for antimicrobial susceptibility testing of bifidobacteria with broth microdilution method, the range of susceptibility to selected antibiotics in 117 animal bifidobacterial strains was examined. Narrow unimodal MIC distributions either situated at the low-end (chloramphenicol, linezolid, and quinupristin/dalfopristin or high-end (kanamycin, neomycin concentration range could be detected. In contrast, the MIC distribution of trimethoprim was multimodal. Data derived from this study can be used as a basis for reviewing or verifying present microbiological breakpoints suggested by regulatory agencies to assess the safety of these micro-organisms intended for the use in probiotics.

  2. Screen and Preliminary Identification of Lactic acid bacteria to Produce Broad-Spectrum Bacteriocin%产广谱细菌素乳酸菌CW3的筛选和初步鉴定

    Institute of Scientific and Technical Information of China (English)

    吕好新; 王巍东; 谈重芳; 杨飞飞; 焦迎春; 王雁萍; 李宗伟

    2013-01-01

    [Objective] CW3 strain was screened and preliminarily identified.[Method] Oxford cup double plate method was adopted to primarily screen spectrum bacteriocin,then excluding acid and hydrogen peroxide disturbance,the protein property of anti-bacteria material was detected,the strain of rescreening was identified.[Result] The supernatant of CW3 strain can inhibit the growth of indicator strains excluded hydrogen peroxide and organic acid.The inhibitive activity decreased largely after treatment with trpsin and pepsin,which can draw that the anti-microbial substances were bacteriocin.The results of identification of physiology and biochemistry preliminarily identified that CW3 strain was a Lactobacillus plantarum.[Conclusion] CW3 strain was a Lactobacillus plantarum,which can generate spectrum bacteriocin.%[目的]对CW3菌株进行筛选,并且进行初步鉴定.[方法]首先采用牛津杯双层平板法进行产广谱细菌素菌株的初筛,再将初筛得到的菌株进行排除酸和过氧化氢干扰,并检测抑菌物质的蛋白质性质,最终对复筛得到的菌株进行鉴定.[结果]试验得出,排除有机酸、过氧化氢等干扰因素后,发酵液仍有抑菌作用;用胰蛋白酶和胃蛋白酶处理后,发酵液抑菌活性急剧下降,确定产生的抑菌物质具有蛋白质性质,是一类细菌素.经过生理生化试验初步鉴定菌株CW3为植物乳杆菌.[结论]菌株CW3是一种能产广谱细菌素的植物乳杆菌.

  3. ANTIMICROBIAL PEPTIDES: AN EFFECTIVE ALTERNATIVE FOR ANTIBIOTIC THERAPY

    Directory of Open Access Journals (Sweden)

    KK PULICHERLA

    2013-01-01

    Full Text Available Extensive use of classical antibiotics has led to the growing emergence of many resistant strains of pathogenic bacteria. Evidence has suggested that cationic antimicrobial peptides (AMP’s are of greatest potential to represent a new class of antibiotics. These peptides have a good scope in current antibiotic research. During the past two decades several AMPs have been isolated from a wide variety of animals (both vertebrates and invertebrates, and plants as well as from bacteria and fungi. These are relatively small (<10kDa, cationic and amphipathic peptides of variable length, sequence and structure. These peptides exhibit broad-spectrum activity against a wide range of microorganisms including gram-positive and gram-negative bacteria, protozoa, yeast, fungi and viruses. Most of these peptides are believed to act by disrupting the plasma membrane leading to the lysis of the cell. Antimicrobial peptides encompass a wide variety of structural motifs such as α -helical peptides, β -sheet peptides, looped peptides and extended peptides. Preparations enriched by a specific protein are rarely easily obtained from natural host cells. Hence, recombinant protein production is frequently the sole applicable procedure. Several fusion strategies have been developed for the expression and purification of small antimicrobial peptides (AMPs in recombinant bacterial expression systems which were produced by cloning. This article aims to review in brief the sources of antimicrobial peptides, diversity in structural features, mode of action, production strategies and insight into the current data on their antimicrobial activity followed by a brief comment on the peptides that have entered clinical trials.

  4. Study of broad-spectrum antibiotics and antiseptics resistance genes in Acinetobacter baumannii strains isolated from burned patients%鲍曼不动杆菌烧伤分离株广谱抗生素及消毒剂耐药基因研究

    Institute of Scientific and Technical Information of China (English)

    程华莉; 潘宇红; 黄璇; 吕国忠; 朱婕; 糜祖煌; 张烽

    2011-01-01

    目的 研究鲍曼不动杆菌烧伤分离株对广谱抗生素的耐药性及所携带的广谱抗生素及消毒剂耐药基因.方法 测定20株分离自烧伤患者的鲍曼不动杆菌对四环素、米诺环素、氯霉素、利福平、复方磺胺甲噁唑5种广谱抗生素的敏感性,PCR检测catB、cmlA、arr-2/3、tetA、tetB、smr-2、emrE、dfrA1、dfrA5、dfrA7、dfrA12、dfrA17、dfrB5、qacE△l-sull和intI 共15种基因.结果 20株细菌对5种抗生素的敏感率分别为10%、100%、0、0和5%.tetB、qacE△l-sull和intl基因检出率均为95%(19/20),其余12种基因为阴性,且一株静脉导管分离株携带了上述3种基因.结论 本组鲍曼不动杆菌烧伤分离株对除米诺环素外的广谱抗生素耐药严重,并携带了四环素类和消毒剂耐药基因.应规范此类抗生素在养殖业中的使用,同时采取措施防止多重耐药菌株利用静脉导管在烧伤科传播.%Objective To investigate the broad-spectrum antibiotics resistance and broad-spectrum antibiotics and antiseptics resistance genes of Acinetobacter baumannii strains isolated from burned patients.Methods Susceptibilities to tetracycline, minocycline, chloramphenicol, rifampicin and trimethoprim-sulfamethoxazole were tested.Subsequently, catB, cmlA, arr-2/3, tetA, tetB, smr-2, emrE, dfrA1, dfrA5, dfr4 7, dfr412, dfrA17, dfrB5, qacE⊿l-sull and intI were detected by PCR.Results Susceptibilities to five broad-spectrum antibiotics were 10%, 100%, 0, 0 and 5% respectively.19/20(95%) isolates carried tetB, qacE⊿l-sull and intI genes while other 12 genes were not detected.Notably, an isolate colonising a central venous catheter carried all three genes mentioned above.Conclusions Acinetobacter baumannii strains isolated from burned patients we studied had serious resistances to broad-spectrum antibiotics except minocycline and carried tetracyclines and antiseptics resistance genes.Accordingly, broad-spectrum antibiotics should be

  5. The impact of an antimicrobial stewardship programme on the use of antimicrobials and the evolution of drug resistance.

    Science.gov (United States)

    Del Arco, A; Tortajada, B; de la Torre, J; Olalla, J; Prada, J L; Fernández, F; Rivas, F; García-Alegría, J; Faus, V; Montiel, N

    2015-02-01

    Misuse of antibiotics can provoke increased bacterial resistance. There are no immediate prospects of any new broad-spectrum antibiotics, especially any with activity against enterobacteria, coming onto the market. Therefore, programmes should be implemented to optimise antimicrobial therapy. In a quasi-experimental study, the results for the pre-intervention year were compared with those for the 3 years following the application of an antimicrobial stewardship programme. We describe 862 interventions carried out as part of the stewardship programme at the Hospital Costa del Sol from 2009 to 2011. We examined the compliance of the empirical antimicrobial treatment with the programme recommendations and the treatment optimisation achieved by reducing the antibiotic spectrum and adjusting the dose, dosing interval and duration of treatment. In addition, we analysed the evolution of the sensitivity profile of the principal microorganisms and the financial savings achieved. 93 % of the treatment recommendations were accepted. The treatment actions taken were to corroborate the empirical treatment (46 % in 2009 and 31 % in 2011) and to reduce the antimicrobial spectrum taking into account the antibiogram results (37 % in 2009 and 58 % in 2011). The main drugs assessed were imipenem/meropenem, used in 38.6 % of the cases, and cefepime (20.1 %). The sensitivity profile of imipenem against Pseudomonas aeruginosa increased by 10 % in 2011. Savings in annual drug spending (direct costs) of 30,000 Euros were obtained. Stewardship programmes are useful tools for optimising antimicrobial therapy. They may contribute to preventing increased bacterial resistance and to reducing the long-term financial cost of antibiotic treatment.

  6. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... how antimicrobial resistance both emerges and proliferates among bacteria. Over time, the use of antimicrobial drugs will result in the development of resistant strains of bacteria, complicating clinician's efforts to select the appropriate antimicrobial ...

  7. Animation of Antimicrobial Resistance

    Science.gov (United States)

    ... Veterinary Home Animal & Veterinary Safety & Health Antimicrobial Resistance Animation of Antimicrobial Resistance Share Tweet Linkedin Pin it ... Veterinary Medicine is cited as the corporate author. Animation Animation of Antimicrobial Resistance (WMV - 19.2MB) 9: ...

  8. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... 08 Animation of Antimicrobial Resistance (text version) Arabic Translation - Animation of Antimicrobial Resistance (WMV - 19.2MB) Chinese Translation - Animation of Antimicrobial Resistance (WMV - 19.2MB) French ...

  9. Antibacterial effects of electrospun chitosan/poly(ethylene oxide) nanofibrous membranes loaded with chlorhexidine and silver.

    Science.gov (United States)

    Song, Jiankang; Remmers, Stefan J A; Shao, Jinlong; Kolwijck, Eva; Walboomers, X Frank; Jansen, John A; Leeuwenburgh, Sander C G; Yang, Fang

    2016-07-01

    To prevent percutaneous device associated infections (PDAIs), we prepared electrospun chitosan/poly(ethylene oxide) (PEO) nanofibrous membrane containing silver nanoparticles as an implantable delivery vehicle for the dual release of chlorhexidine and silver ions. We observed that the silver nanoparticles were distributed homogeneously throughout the fibers, and a fast release of chlorhexidine in 2days and a sustained release of silver ions for up to 28days. The antibacterial efficacy of the membranes against Staphylococcus aureus showed that the membranes exhibited an obvious inhibition zone upon loading with either chlorhexidine (20μg or more per membrane) or AgNO3 (1 and 5wt% to polymer). Furthermore, long-term antibacterial effect up to 4days was verified using membranes containing 5wt% AgNO3. The results suggest that the membranes have strong potential to act as an active antibacterial dressing for local delivery of antibacterial agents to prevent PDAIs. PMID:26970025

  10. Standardized testing with chlorhexidine in perioperative allergy – a large single-centre evaluation

    DEFF Research Database (Denmark)

    Schjørring Opstrup, Morten; Malling, Hans-Jørgen; Krøigaard, Mogens;

    2014-01-01

    BACKGROUND: Perioperative allergic reactions to chlorhexidine are often severe and easily overlooked. Although rare, the prevalence remains unknown. Correct diagnosis is crucial, but no validated provocation model exists, and other diagnostic tests have never been evaluated. The aims were...... to estimate 1) the prevalence of chlorhexidine allergy and 2) the specificity and sensitivity for diagnostic tests for chlorhexidine allergy. METHODS: We included all patients investigated for suspected perioperative allergic reactions in the Danish Anaesthesia Allergy Centre during 2004-2012. The following...... tests were performed: specific IgE (Immunocap(®) , Phadia AB, Sweden), histamine release test (HR) (RefLab ApS, Denmark), skin prick test (SPT) and intradermal test (IDT). Positivity criteria: specific IgE > 0.35 kUA/l; HR class 1-12; SPT mean wheal diameter ≥ 3 mm; IDT mean wheal diameter ≥ twice...

  11. Effect of chlorhexidine and benzydamine mouthwashes on mucositis induced by therapeutic irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Samaranayake, L.P.; MacFarlane, T.W.; Hunter, I.P.; Robertson, A.G.; MacFarlane, G.; Soutar, D.S.; Ferguson, M.M.

    1988-05-01

    The efficacy of Benzydamine as a mouthwash was compared with chlorhexidine in two groups of patients receiving radiotherapy for oral carcinoma. Mucositis and pain were recorded over a 6 week period and oral carriage of Candida species, coliforms and Staphylococcus aureus was assessed using an oral rinse technique. There was no significant difference in the mucositis scores, overall pain scores or the yeast and bacterial species isolated between the two treatment groups. However, 58% (7 out of 12) and 92% (12 out of 13) patients reported oral discomfort when rinsing the mouth with chlorhexidine and benzydamine, respectively. In both groups, the most common coliform isolated was Klebsiella pneumoniae and the carriage of yeasts was significantly greater than that of coliforms. These results indicate that, although the individual patient acceptance of chlorhexidine is better than benzydamine, there is little difference between the two mouthwashes both in controlling pain and mucositis or in the oral carriage of the micro-organisms studied.

  12. The effect of chlorhexidine and benzydamine mouthwashes on mucositis induced by therapeutic irradiation

    International Nuclear Information System (INIS)

    The efficacy of Benzydamine as a mouthwash was compared with chlorhexidine in two groups of patients receiving radiotherapy for oral carcinoma. Mucositis and pain were recorded over a 6 week period and oral carriage of Candida species, coliforms and Staphylococcus aureus was assessed using an oral rinse technique. There was no significant difference in the mucositis scores, overall pain scores or the yeast and bacterial species isolated between the two treatment groups. However, 58% (7 out of 12) and 92% (12 out of 13) patients reported oral discomfort when rinsing the mouth with chlorhexidine and benzydamine, respectively. In both groups, the most common coliform isolated was Klebsiella pneumoniae and the carriage of yeasts was significantly greater than that of coliforms. These results indicate that, although the individual patient acceptance of chlorhexidine is better than benzydamine, there is little difference between the two mouthwashes both in controlling pain and mucositis or in the oral carriage of the micro-organisms studied. (author)

  13. Chlorhexidine spray as an adjunct in the control of dental biofilm in children with special needs.

    Science.gov (United States)

    Viana, Gilberg Resende; Teiltelbaum, Ana Paula; dos Santos, Fábio André; Sabbagh-Haddad, Aida; Guaré, Renata Oliveira

    2014-01-01

    The aim of this study was to evaluate the clinical effectiveness of .12% chlorhexidine applied via spray and the acceptance. A total of 26 individuals with mental health issues, aged 7-14, were included into two groups: placebo (control, n = 13) and chlorhexidine (experimental, n = 13). Both groups received two daily applications of spray during 2 months. The periodontal conditions were evaluated by the simplified oral hygiene index (OHI-S) and gingival index (GI). The evaluation of acceptance of the application method (spray) was assessed by questionnaire. Data were analyzed with nonparametric tests, with a significance level of 5%. Regarding the OHI-S index, only the experimental group showed significant change during the evaluations (p < 0.001). Regarding the GI, both groups showed significant changes during the evaluations. The method of application was well accepted by patients and caregivers, and .12% chlorhexidine solution applied via spray significantly reduced the rates of dental and gingival biofilm.

  14. Antimicrobial activity of different filling pastes for deciduous tooth treatment

    Directory of Open Access Journals (Sweden)

    Bruna Feltrin ANTONIAZZI

    2015-01-01

    Full Text Available Guedes-Pinto paste is the filling material most employed in Brazil for endodontic treatment of deciduous teeth; however, the Rifocort® ointment has been removed. Thus, the aim of this study was to investigate the antimicrobial potential of filling pastes, by proposing three new pharmacological associations to replace Rifocort® ointment with drugs of already established antimicrobial power: Nebacetin® ointment, 2% Chlorhexidine Gluconate gel, and Maxitrol® ointment. A paste composed of Iodoform, Rifocort® ointment and Camphorated Paramonochlorophenol (CPC was employed as the gold standard (G1. The other associations were: Iodoform, Nebacetin® ointment and CPC (G2; Iodoform, 2% Chlorhexidine Digluconate gel and CPC (G3; Iodoform, Maxitrol® ointment and CPC (G4. The associations were tested for Staphylococcus aureus (S. aureus, Streptococcus mutans (S. mutans, Streptococcus oralis (S. oralis, Enterococcus faecalis (E. faecalis, Escherichia coli (E. coli, and Bacillus subtilis (B. subtilis, using the methods of dilution on solid medium – orifice agar – and broth dilution. The results were tested using statistical analysis ANOVA and Kruskal-Wallis. They showed that all the pastes had a bacteriostatic effect on all the microorganisms, without any statistically significant difference, compared with G1. S. aureus was statistically significant (multiple comparison test of Tukey, insofar as G2 and G3 presented the worst and the best performance, respectively. All associations were bactericidal for E. coli, S. aureus, S. mutans and S. oralis. Only G3 and G4 were bactericidal for E. faecalis, whereas no product was bactericidal for B. subtilis. Thus, the tested pastes have antimicrobial potential and have proved acceptable for endodontic treatment of primary teeth.

  15. Comparison of Antibacterial Effect of Fluoride and Chlorhexidine on Two Cariogenic Bacteria: An in Vitro Study

    Directory of Open Access Journals (Sweden)

    Poureslami HR

    2014-09-01

    Full Text Available Statement of problem: Dental plaque is the main source for dental caries and there is no proper vaccine that can affect dental plaques. Objectives: Daily use of an efficient anti-plaque product can be very beneficial in plaque control and, thus, prevention of caries. This study aims to evaluate the antibacterial effects of four products of Chlorhexidine and Fluoride on two types of cariogenic bacteria. Materials and Methods: In this in vitro study, the antibacterial effect of Chlorhexidine and Fluoride (gel and solution against Streptococci Sanguis and Sobrinus was evaluated. Chlorhexidine gluconate 1% gel (Corosodyl, France, Chlorhexidine gluconate 2% solution (Consepsis, Ultradent, US, Sodium fluoride 0.2% solution (Oral-B, US and Acidulated Phosphate Fluoride 1.23% gel ( Denti-Care, Canada were used. The disc diffusion method was used for testing bacterial sensitivity. The data were analyzed using paired t-test and Chi-square test. Results: In comparison with the negative control, each of the four gels and solutions showed antibacterial effects but the effects were not statistically significant for fluoride solution (P=0.217. For S. Sobrinus, the mean diameter of inhibition zone around the discs coated with fluoride gel (F g, fluoride solution (F s, Chlorhexidine gel (CHX g and Chlorhexidine solution (CHX s were 19, 9, 21.5 and 27.5mm, respectively. For S. Sanguis, the mean diameter of inhibition zone around the discs coated with F g, F s, CHX g and CHX s were 17, 11, 17 and 25mm, respectively. CHX s had the most effect on both bacteria and F s had the least. CHX g and F g were less effective than CHX s, respectively. Conclusion: The results demonstrated that 2% CHX s and 1.23% F g can be effective on inhibition of the growth of some of cariogenic bacteria. Therefore, these agents can be used in the prevention of Early Childhood Caries.

  16. Effect of chlorhexidine on oral airway biofilm formation of Staphylococcus epidermidis

    Directory of Open Access Journals (Sweden)

    Ünase Büyükkoçak

    2015-12-01

    Full Text Available Objective: Biofilm formation of microorganisms on the surface of airways may lead to supraglottic colonization that may cause lower respiratuar tract infections. Studies searching the efficiency of local disinfectants on biofilm formation are limited. The aim of this study was to investigate the effects of chlorhexidine coated airways on biofilm formation of Staphylococcus epidermidis. Methods: Culture and electron microscopy methods were used for biofilm assessment. Airways were divided into two groups to investigate the effects of chlorhexidine on number of bacteria attached to the airway and biofilm formation. Group 1(control: naive material, S. epidermidis, Group 2: chlorhexidine coated material, S. epidermidis. No process was applied in Group 1. Chlorhexidine gluconate (0.2% was sprayed on the surface of naive material for four seconds and then left to dry in air, in Group to. Number of bacteria attached to the airway were counted by microbiological methods and biofilm formation was shown by Scanning Electron Microscope (SEM. Mann-Whitney u test was performed for statistical analyses. Results: In Group 2, bacteria numbers were 1x102-8x102 cfu/ml, whereas they were 3x103-1x104 cfu/ml in Group 1. Chlorhexidine decreased number of microorganisms attached to the airways with statistical significance (p=0.04. The results of the electron microscopic evaluation were in accordance with the acteriological findings. Conclusion: This study has shown that chlorhexidine coating can successfully reduce the number of adhered bacteria and biofilm formation on airways. J Microbiol Infect Dis 2015;5(4: 162-166

  17. Antimicrobial activity of leaf extracts of Justicia adhatoda L. in comparison with vasicine

    Institute of Scientific and Technical Information of China (English)

    Rashmi Pa; Linu Mathew

    2012-01-01

    Objective: To ascertain the antimicrobial activity of methanolic leaf extracts of Justicia adhatoda and vasicine against Staphylococcus aureus, Streptococcus pyogenes, Serratia marcescens, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Cryptococcus neoformans and Aspergillus flavus. Methods: The antimicrobial activity of the concentrated leaf extracts of J. adhatoda was evaluated by determination of the diameter of zone of inhibition against bacteria and fungi. 25μg ml-1 concentration was used to check the antimicrobial activity of plant extracts and vasicine. Minimum inhibitory concentrations and minimum microbicidal concentrations were determined against all the pathogens. Sensitivity of the pathogens was also checked with four standard antibiotics, ciprofloxacin and ofloxacin for bacteria and nystatin and amphotericin B for fungi. Results: The phytochemical studies revealed the presence of alkaloids in the extracts were active against both bacteria and fungi. Studies on the minimum inhibitory concentration of the extracts on the test organisms showed that the lowest minimum inhibitory concentration and minimum microbicidal concentrations were demonstrated against Serratia marcescens, Escherichia coli and Pseudomonas aeruginosa and the highest minimum inhibitory concentration was exhibited against Staphylococcus aureus, Streptococcuspyogenes, Klebsiella pnuemoniae. Among fungi Aspergillus flavus showed lowest minimum inhibitory concentration whereas Candida albicans and Cryptococcus neoformans showed highest minimum inhibitory concentration. Conclusion: The present study revealed that J. adhatoda has broad spectrum of antimicrobial activity and a potential source of antimicrobial agents that could be useful for chemotherapy and control of infectious diseases.

  18. SCREENING OF ANTIMICROBIAL ACTIVITY AND GENES CODING POLYKETIDE SYNTHETASE AND NONRIBOSOMAL PEPTIDE SYNTHETASE OF ACTINOMYCETE ISOLATES

    Directory of Open Access Journals (Sweden)

    Silvia Kovácsová

    2013-12-01

    Full Text Available The aim of this study was to observe antimicrobial activity using agar plate diffusion method and screening genes coding polyketide synthetase (PKS-I and nonribosomal peptide synthetase (NRPS from actinomycetes. A total of 105 actinomycete strains were isolated from arable soil. Antimicrobial activity was demonstrated at 54 strains against at least 1 of total 12 indicator organisms. Antifungal properties were recorded more often than antibacterial properties. The presence of PKS-I and NRPS genes were founded at 61 of total 105 strains. The number of strains with mentioned biosynthetic enzyme gene fragments matching the anticipated length were 19 (18% and 50 (47% respectively. Overall, five actinomycete strains carried all the biosynthetical genes, yet no antimicrobial activity was found against any of tested pathogens. On the other hand, twenty-one strains showed antimicrobial activity even though we were not able to amplify any of the PKS or NRPS genes from them. Combination of the two methods showed broad-spectrum antimicrobial activity of actinomycetes isolated from arable soil, which indicate that actinomycetes are valuable reservoirs of novel bioactive compounds.

  19. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... More in Antimicrobial Resistance National Antimicrobial Resistance Monitoring System ... Note: If you need help accessing information in different file formats, see Instructions for Downloading ...

  20. Toxicity of chlorhexidine on odontoblast-like cells

    Directory of Open Access Journals (Sweden)

    Fernanda Campos Rosetti Lessa

    2010-02-01

    Full Text Available Chlorhexidine gluconate (CHX is recommended for a number of clinical procedures and it has been pointed out as a potential cavity cleanser to be applied before adhesive restoration of dental cavities. OBJECTIVE: As CHX may diffuse through the dentinal tubules to reach a monolayer of odontoblasts that underlies the dentin substrate, this study evaluated the cytotoxic effects of different concentrations of CHX on cultured odontoblast-like cells (MDPC-23. MATERIAL AND METHODS: Cells were cultured and exposed to CHX solutions at concentrations of 0.06%, 0.12%, 0.2%, 1% and 2%. Pure culture medium (α-MEM and 3% hydrogen peroxide were used as negative and positive control, respectively. After exposing the cultured cells to the controls and CHX solutions for 60 s, 2 h or 60 s with a 24-h recovery period, cell metabolism (MTT assay and total protein concentration were evaluated. Cell morphology was assessed under scanning electron microscopy. CHX had a dose-dependent toxic effect on the MDPC-23 cells. RESULTS: Statistically significant difference was observed when the cells were exposed to CHX in all periods (p<0.05. Significant difference was also determined for all CHX concentrations (p<0.05. The 60-s exposure time was the least cytotoxic (p<0.05, while exposure to CHX for 60 s with a 24-h recovery period was the most toxic to the cells (p<0.05. CONCLUSION: Regardless of the exposure time, all CHX concentrations had a high direct cytotoxic effect to cultured MDPC-23 cells.

  1. Antibacterial dental composites with chlorhexidine and mesoporous silica.

    Science.gov (United States)

    Zhang, J F; Wu, R; Fan, Y; Liao, S; Wang, Y; Wen, Z T; Xu, X

    2014-12-01

    One of the leading causes for the failure of dental composite restorations is secondary caries. Effectively inhibiting cariogenic biofilms and reducing secondary caries could extend the service life of composite restorations. Dental composites releasing antibacterial agents such as chlorhexidine (CHX) have shown biofilm-inhibitory efficacy, but they usually have poor physical and mechanical properties. Herein, we present a study of a new method to encapsulate and release CHX from dental composite using mesoporous silica nanoparticles (MSNs). SBA-15 MSNs were synthesized according to a reported procedure. CHX (62.9 wt%) was encapsulated into dried MSN from 0.3 M CHX ethanol solution. The dental composites containing 0% (control), 3%, 5%, and 6.3% CHX or the same amounts of CHX entrapped in MSN (denoted as CHX@MSN) were fabricated with methacrylate monomers and silanized glass fillers (CHX or CHX@MSN + glass filler particle = 70 wt%). The monomer mixture consisted of bisphenol A glycidyl methacrylate (BisGMA), hexanediol dimethacrylate (HDDMA), ethoxylated bisphenol A dimethacrylate (EBPADMA), and urethane dimethacrylates (UEDMA) at a weight ratio of 40:30:20:10. The composites were tested for CHX release and recharge, flexural strength and modulus (at 24 hr and 1 mo), surface roughness, in vitro wear, and antibacterial activity against Streptococcus mutans and Lactobacillus casei (in both planktonic growth and biofilm formation). The results showed that the composites with CHX@MSN largely retained mechanical properties and smooth surfaces and showed controlled release of CHX over a long time. In contrast, the composites with directly mixed CHX showed reduced mechanical properties, rough surfaces, and burst release of CHX in a short time. The composites with CHX either directly mixed or in MSN showed strong inhibition to S. mutans and L. casei. This research has demonstrated the successful application of MSNs as a novel nanotechnology in dental materials to inhibit

  2. The synthesis and characterization of analogs of the antimicrobial compound squalamine: 6 beta-hydroxy-3-aminosterols synthesized from hyodeoxycholic acid.

    Science.gov (United States)

    Jones, S R; Kinney, W A; Zhang, X; Jones, L M; Selinsky, B S

    1996-10-01

    Analogs of the aminosterol antimicrobial agent squalamine have been synthesized beginning from hyodeoxycholic acid. After carboxylic acid esterification and oxidation of both alcohol functions to ketones, the A/B ring junction was converted from cis to trans by acid-catalyzed isomerization. Different polyamines were added to the 3-keto group by reductive amination, yielding both the 3 alpha and 3 beta addition products. The synthetic products exhibited potent, broad-spectrum antimicrobial activity similar to that of the parent compound. Changing the identity of the polyamine or the stereochemistry of addition has little effect upon antimicrobial activity but appears to change the selectivity of the agents. The analogs are synthesized with high yield from inexpensive starting materials and are promising alternatives to squalamine as potential antibiotics. PMID:8910969

  3. Antimicrobial Activity of Three Root Canal Irrigants on Enterococcus Faecalis: An in Vitro Study

    OpenAIRE

    Ahangari, Zohreh; Samiee, Mohammad; Yolmeh, Mohammad Amin; Eslami, Gita

    2008-01-01

    INTRODUCTION: The aim of this study was to compare the antimicrobial effects of 2.5% Sodium hypochlorite (NaOCl), 2% Chlorhexidine Gluconate (CHX) and BioPure MTAD (MTAD) on Enterococcus (E) faecalis-contaminated root canals of human extracted teeth. MATERIALS AND METHODS: Seventy human intact extracted single-rooted teeth with straight root canal randomly divided into 5 groups: positive control (n=5), negative control (n=5), 2.5% NaOCl (n=20), 2% CHX (n=20), and MTAD (n=20). Each tooth was i...

  4. Transgenic Brassica juncea plants expressing MsrA1, a synthetic cationic antimicrobial peptide, exhibit resistance to fungal phytopathogens.

    Science.gov (United States)

    Rustagi, Anjana; Kumar, Deepak; Shekhar, Shashi; Yusuf, Mohd Aslam; Misra, Santosh; Sarin, Neera Bhalla

    2014-06-01

    Cationic antimicrobial peptides (CAPs) have shown potential against broad spectrum of phytopathogens. Synthetic versions with desirable properties have been modeled on these natural peptides. MsrA1 is a synthetic chimera of cecropin A and melittin CAPs with antimicrobial properties. We generated transgenic Brassica juncea plants expressing the msrA1 gene aimed at conferring fungal resistance. Five independent transgenic lines were evaluated for resistance to Alternaria brassicae and Sclerotinia sclerotiorum, two of the most devastating pathogens of B. juncea crops. In vitro assays showed inhibition by MsrA1 of Alternaria hyphae growth by 44-62 %. As assessed by the number and size of lesions and time taken for complete leaf necrosis, the Alternaria infection was delayed and restricted in the transgenic plants with the protection varying from 69 to 85 % in different transgenic lines. In case of S. sclerotiorum infection, the lesions were more severe and spread profusely in untransformed control compared with transgenic plants. The sclerotia formed in the stem of untransformed control plants were significantly more in number and larger in size than those present in the transgenic plants where disease protection of 56-71.5 % was obtained. We discuss the potential of engineering broad spectrum biotic stress tolerance by transgenic expression of CAPs in crop plants.

  5. Transgenic Brassica juncea plants expressing MsrA1, a synthetic cationic antimicrobial peptide, exhibit resistance to fungal phytopathogens.

    Science.gov (United States)

    Rustagi, Anjana; Kumar, Deepak; Shekhar, Shashi; Yusuf, Mohd Aslam; Misra, Santosh; Sarin, Neera Bhalla

    2014-06-01

    Cationic antimicrobial peptides (CAPs) have shown potential against broad spectrum of phytopathogens. Synthetic versions with desirable properties have been modeled on these natural peptides. MsrA1 is a synthetic chimera of cecropin A and melittin CAPs with antimicrobial properties. We generated transgenic Brassica juncea plants expressing the msrA1 gene aimed at conferring fungal resistance. Five independent transgenic lines were evaluated for resistance to Alternaria brassicae and Sclerotinia sclerotiorum, two of the most devastating pathogens of B. juncea crops. In vitro assays showed inhibition by MsrA1 of Alternaria hyphae growth by 44-62 %. As assessed by the number and size of lesions and time taken for complete leaf necrosis, the Alternaria infection was delayed and restricted in the transgenic plants with the protection varying from 69 to 85 % in different transgenic lines. In case of S. sclerotiorum infection, the lesions were more severe and spread profusely in untransformed control compared with transgenic plants. The sclerotia formed in the stem of untransformed control plants were significantly more in number and larger in size than those present in the transgenic plants where disease protection of 56-71.5 % was obtained. We discuss the potential of engineering broad spectrum biotic stress tolerance by transgenic expression of CAPs in crop plants. PMID:24452332

  6. The metabolically active subpopulation in Pseudomonas aeruginosa biofilms survives exposure to membrane-targeting antimicrobials via distinct molecular mechanisms

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Pamp, Sünje Johanna; Nilsson, Martin;

    2012-01-01

    have found that membrane-targeting antimicrobials such as colistin, EDTA, SDS, and chlorhexidine specifically kill the inactive subpopulation in P. aeruginosa biofilms, whereas the active subpopulation survives exposure to these compounds. Because treatment of P. aeruginosa biofilms with the membrane......-targeting compounds colistin, EDTA, SDS, and chlorhexidine resulted in the same spatial distribution of live and dead bacteria, we investigated whether tolerance to these compounds originated from the same molecular mechanisms. Development of colistin-tolerant subpopulations was found to depend on the pmr genes......, but does not depend on the pmr, mexAB-oprM, mexPQ-opmE, or muxABC-opmB genes. Tolerance to SDS and EDTA in P. aeruginosa biofilms is linked to metabolically active cells, but does not depend on the pmr, mexAB, mexCD, mexPQ, or muxABC genes. Our data suggest that the active subpopulation in P. aeruginosa...

  7. Temporin-SHf, a New Type of Phe-rich and Hydrophobic Ultrashort Antimicrobial Peptide*

    Science.gov (United States)

    Abbassi, Feten; Lequin, Olivier; Piesse, Christophe; Goasdoué, Nicole; Foulon, Thierry; Nicolas, Pierre; Ladram, Ali

    2010-01-01

    Because issues of cost and bioavailability have hampered the development of gene-encoded antimicrobial peptides to combat infectious diseases, short linear peptides with high microbial cell selectivity have been recently considered as antibiotic substitutes. A new type of short antimicrobial peptide, designated temporin-SHf, was isolated and cloned from the skin of the frog Pelophylax saharica. Temporin-SHf has a highly hydrophobic sequence (FFFLSRIFa) and possesses the highest percentage of Phe residues of any known peptide or protein. Moreover, it is the smallest natural linear antimicrobial peptide found to date, with only eight residues. Despite its small size and hydrophobicity, temporin-SHf has broad-spectrum microbicidal activity against Gram-positive and Gram-negative bacteria and yeasts, with no hemolytic activity. CD and NMR spectroscopy combined with restrained molecular dynamics calculations showed that the peptide adopts a well defined non-amphipathic α-helical structure from residue 3 to 8, when bound to zwitterionic dodecyl phosphocholine or anionic SDS micelles. Relaxation enhancement caused by paramagnetic probes showed that the peptide adopts nearly parallel orientations to the micelle surface and that the helical structure is stabilized by a compact hydrophobic core on one face that penetrates into the micelle interior. Differential scanning calorimetry on multilamellar vesicles combined with membrane permeabilization assays on bacterial cells indicated that temporin-SHf disrupts the acyl chain packing of anionic lipid bilayers, thereby triggering local cracks and microbial membrane disintegration through a detergent-like effect probably via the carpet mechanism. The short length, compositional simplicity, and broad-spectrum activity of temporin-SHf make it an attractive candidate to develop new antibiotic agents. PMID:20308076

  8. Facile eco-friendly synthesis of novel chromeno[4,3-b]pyridine-2,5-diones and evaluation of their antimicrobial and antioxidant properties

    Indian Academy of Sciences (India)

    Satyanarayana Reddy Jaggavarapu; Anand Solomon Kamalakaran; Ventkata Prasad Jalli; Sravan Kumar Gangisetty; Munusswamy Ramanujam Ganesh; Gopikrishna Gaddamanugu

    2014-01-01

    Rapid and facileaccess to novel chromeno[4,3-b]pyridine-2,5-dione derivatives was achieved by a mild base catalysed reaction of 4-chloro-3-formylcoumarin and acetoacetamides in PEG-300 as recyclable solvent. The compounds were evaluated for their antimicrobial activities against 3 Gram-positive and 3 Gram-negative bacteria (Staphylococcus epidermis, Vibrio parahaemolyticus, Bacillus subtilis, Escherichia coli, Staphylococcus aureus and Klebsiella pneumonia) with Cefotaxime control. They were further subjected to antioxidant studies using DPPH test with ascorbic acid control. While compounds 5d and 5k showed promising broad spectrum antibacterial properties against all the evaluated bacteria, compound 5g exhibited good antioxidant properties.

  9. The bactericidal activity of a teat dip containing chlorhexidine and cetrimide.

    Science.gov (United States)

    King, J S; Morant, S V; Bramley, A J

    1977-11-19

    Using an in vivo test on teat skin the disinfectant activity of a teat dip containing chlorhexidine and cetrimide was compared with two iodophor solutions, one containing the recommended concentration of 0.5 per cent available iodine and the other a 10-fold dilution of this (0.05 per cent iodine). The test organisms used were Staphylococcus aureus and Escherichia coli and for both species the 0.5 per cent iodophor was significantly more bactericidal than either the diluted iodophor or the chlorhexidine/cetrimide teat dip (P less than 0.01). In the test against S aureus, chlorhexidine/cetrimide and the 0.05 per cent iodophor showed similar bactericidal activity, but the iodophor was significantly more bactericidal against E coli (P less than 0.01). It is argued that due to its low bactericidal activity this formulation of chlorhexidine/cetrimide is likely to be inferior to 0.5 per cent iodophor solution as a disinfectant teat dip. PMID:339477

  10. Effect of a chlorhexidine-containing brush-on gel on peri-implant mucositis

    DEFF Research Database (Denmark)

    Hallström, H; Lindgren, S; Twetman, S

    2016-01-01

    OBJECTIVE: The aim was to evaluate the effect of a chlorhexidine-containing brush-on gel when used as supplement to oral hygiene instructions and mechanical debridement, on peri-implant mucositis in adults. MATERIALS AND METHODS: The study group consisted of 38 adults (48-87 years.) with peri-implant...... of peri-implant mucositis....

  11. EFFECT OF A COMBINED CHLORHEXIDINE AND NAF MOUTHRINSE - AN IN-VIVO HUMAN CARIES MODEL STUDY

    NARCIS (Netherlands)

    ULLSFOSS, BN; OGAARD, B; ARENDS, J; RUBEN, J; ROLLA, G; AFSETH, J

    1994-01-01

    Chlorhexidine (CHX) is probably the most widely used and the most potent chemical plaque inhibitory agent, whereas fluoride (F-) is the only truly accepted anticaries agent available at present. As they have discrete mechanisms of action, a combination effect of these agents on human dental caries m

  12. Superiority of chlorhexidine 2%/alcohol 70% wipes in decontaminating ultrasound equipment.

    Science.gov (United States)

    Shukla, Bhavin; Howell, Victoria; Griffiths, Alicia; Thoppil, Anita; Liu, Monica; Carter, Joseph; Young, Peter

    2014-08-01

    Ultrasound equipment is known to act as a reservoir for potentially pathogenic organisms. The aims of these studies were to establish current cleaning practices, to review the extent of bacterial contamination of ultrasound equipment in our hospital, to establish an effective cleaning regimen and to ensure that cleaning does not cause damage. A questionnaire was sent to all acute NHS hospitals in England to establish current cleaning practices. A review of our current practice was performed to establish the extent of bacterial contamination of ultrasound equipment currently in use. Laboratory studies compared cleaning the probes with soap and water with decontaminating with a chlorhexidine 2% and alcohol 70% wipe, including quantifying the residual effect. Accelerated aging was performed on the probe and staff surveyed to establish potential problems with using the wipes on the probe. The survey revealed that a variety of cleaning methods were used to decontaminate ultrasound probes; 57% of our ultrasound machines were contaminated with bacteria. The laboratory studies showed superiority of the chlorhexidine and alcohol wipes over soap and water due to a residual effect, both immediately after cleaning and after 24 hours. The staff survey demonstrated no apparent change in function of the probe after cleaning with the chlorhexidine wipes. Cleaning ultrasound probes with chlorhexidine and alcohol wipes is effective and provides additional protection against bacterial contamination due to its residual effect, and appears in the short term to have no detrimental effect on the probe. PMID:27433210

  13. Evaluation of Antibacterial Efficacy of MTA with and without Additives Like Silver Zeolite and Chlorhexidine

    Science.gov (United States)

    Patil, Anand; Giriyappa, Ramesh Halebathi; Singh, Thakur Veerandar; Jyotsna, Sistla Venkata; Rairam, Surabhi

    2016-01-01

    Introduction Microorganisms, predominantly Enterococcus faecalis are found responsible in the progression of pulpal, periradicular diseases and in endodontic failures. Unsuccessful conventional treatment might necessitate the need for a surgical approach; where in retrograde restorative materials are used to seal the apex. Among the root end filling materials, Mineral Trioxide Aggregate (MTA) is considered biocompatible and is most commonly used in clinical applications but it has limited antibacterial activity. Metallic silver and chlorhexidine have been added into various dental materials to enhance the antibacterial activity. Aim This study aimed to compare the antibacterial effect of MTA, MTA mixed with silver zeolite and MTA mixed with chlorhexidine against Enterococcus faecalis. Materials and Methods Test materials used in the study were divided into three groups namely Group 1- MTA, Group 2-MTA + Silver Zeolite, Group 3-MTA + Chlorhexidine. Direct contact test was done by placing a standardized suspension of Enterococcus faecalis on the test materials in a 96 well microtiter plate. The bacterial growth was measured spectrophotometrically using ELISA reader at intervals of one, three and seven days. Statistical Analysis Data was collected by recording the optical density and analyzed using two-way ANOVA and Tukey’s multiple post hoc test followed by paired-t test. Results and Conclusion All test groups showed antibacterial activity against Enterococcus faecalis at day one, three and seven. MTA with silver zeolite showed the maximum antibacterial activity followed by MTA with 2% chlorhexidine. The least antibacterial effect was shown by MTA mixed with sterile water.

  14. Delmopinol-induced matrix removal facilitates photodynamic therapy and chlorhexidine methods for disinfecting mixed oral biofilms

    Science.gov (United States)

    Rogers, Stephen Christopher

    It is often observed that the slimy matrixes of various bacterial-formed biofilms can limit their disinfection. This investigation demonstrated that disinfection effectiveness by either photodynamic therapy (PDT) or chlorhexidine irrigation is significantly improved by collapse of that matrix using the non-bactericidal reagent delmopinol as part of the treatment sequence. Cyclic shear-producing conditions were used to grow 4-day, whole salivary and growth media biofilms on glow-discharge-treated polystyrene (N=46) and mini-germanium internal reflection prisms to serve in a periodontal crypt model of disinfection by either methylene-blue-mediated PDT or by chlorhexidine irrigation. Assays for bacterial viability, with and without treatments, were performed by alamarBlueRTM fluorescent methods, statistically applied (ANOVA, Tukey's HSD). Multiple Attenuated Internal Reflection Infrared (MAIR-IR) assays confirmed selective removal of the predominantly polysaccharide matrix materials by the delmopinol treatment, but not by equivalent water or chlorhexidine methods. Confocal-IR microscopy showed that the delmopinol reagent, alone, caused about one-third of each wet biofilm to be removed, while bacterial re-growth was confirmed by alamarBlueRTM assay. Chlorhexidine and PDT suppression of bacterial activity without regrowth was significantly improved with the added delmopinol treatment, and is likely to provide similarly beneficial results in the effective disinfection of diverse biofilms in many settings.

  15. The Mouthwash War - Chlorhexidine vs. Herbal Mouth Rinses: A Meta-Analysis

    Science.gov (United States)

    Hussain, Sajjid; Wadgave, Umesh; Duraiswamy, Prabu; Ravi, K.

    2016-01-01

    Introduction Mouthwashes are often prescribed in dentistry for prevention and treatment of several oral conditions. In the recent times the use of naturally occurring products what is otherwise known as grandmothers remedy are used on a large scale. This has now called for a newer age of mouth washes but is the new age mouth washes at par with the gold standard or even better than them this study investigates. Aim The aim of the present study was to compare the effect of two broad categories of mouth washes namely chlorhexidine and herbal mouth washes. Materials and Methods Eleven randomized control studies were pooled in for the meta-analysis. The search was done from the Pub Med Central listed studies with the use keywords with Boolean operators (chlorhexidine, herbal, mouth wash, randomized control trials). The fixed effects model was used for analysis. Results This meta-analysis brings to light, the fact that a wide range of newer herbal products are now available. As with a plethora of herbal mouthwashes available it is the need of the hour to validate their potential use and recommendation. This study found that only two studies favor the use of herbal products and four studies favor the use of chlorhexidine, of the 11 studies that were analyzed. Conclusion More studies are required under well controlled circumstances to prove that herbal products can equate or replace the ‘gold standard’ chlorhexidine. Herbal products are heterogeneous in nature, their use should be advised only with more scientific proof. PMID:27437366

  16. Caries-inhibiting effect of chlorhexidine varnish in pits and fissures.

    NARCIS (Netherlands)

    Zhang, Q.; Hof, M.A. van 't; Truin, G.J.; Bronkhorst, E.M.; Palenstein Helderman, W.H. van

    2006-01-01

    Evidence regarding the caries-inhibiting effect of chlorhexidine varnish is inconclusive. This study investigated the caries-inhibiting effect of the varnish EC40 on pits and fissures of first permanent molars. A two-year randomized controlled trial was carried out among 461 six- to seven-year-old c

  17. Antimicrobial Peptides as Mediators of Innate Immunity in Teleosts

    Directory of Open Access Journals (Sweden)

    Barbara A. Katzenback

    2015-09-01

    Full Text Available Antimicrobial peptides (AMPs have been identified throughout the metazoa suggesting their evolutionarily conserved nature and their presence in teleosts is no exception. AMPs are short (18–46 amino acids, usually cationic, amphipathic peptides. While AMPs are diverse in amino acid sequence, with no two AMPs being identical, they collectively appear to have conserved functions in the innate immunity of animals towards the pathogens they encounter in their environment. Fish AMPs are upregulated in response to pathogens and appear to have direct broad-spectrum antimicrobial activity towards both human and fish pathogens. However, an emerging role for AMPs as immunomodulatory molecules has become apparent—the ability of AMPs to activate the innate immune system sheds light onto the multifaceted capacity of these small peptides to combat pathogens through direct and indirect means. Herein, this review focuses on the role of teleost AMPs as modulators of the innate immune system and their regulation in response to pathogens or other exogenous molecules. The capacity to regulate AMP expression by exogenous factors may prove useful in modulating AMP expression in fish to prevent disease, particularly in aquaculture settings where crowded conditions and environmental stress pre-dispose these fish to infection.

  18. Antimicrobial, antioxidant activities and chemical composition of selected Thai spices

    Directory of Open Access Journals (Sweden)

    Juraithip Wungsintaweekul

    2010-12-01

    Full Text Available Nine volatile oils and six methanol extracts from Ocimum americanum, O. basilicum, O. sanctum, Citrus hystrix,Alpinia galanga, Curcuma zedoaria, Kaempferia parviflora and Zingiber cassumunar were assessed for antimicrobial andantioxidant activities. The volatile oils and extracts were investigated against eight bacteria and three fungi. The resultsillustrated that O. americanum volatile oil exhibited broad spectrum activity against tested bacteria with the MICs ranging1.4-3.6 mg/ml and Candida spp. with the MICs ranging from 0.5-0.6 mg/ml. The O. sanctum volatile oil showed a considerableactivity against only Candida spp. with the MICs ranging from 0.8-1.4 mg/ml. Interestingly, growth of Mycobacteriumphlei was inhibited by the volatiles of O. americanum, C. hystrix peel, and C. zedoaria with MIC of 1.7, 3.5 and 1.2 mg/ml,respectively. For antioxidant activity evaluation, the methanol extracts of C. hystrix (leaf and peel and K. parviflora hadpotent antioxidant activity by the radical-scavenging DPPH method with IC50 of 24.6, 66.3 and 61.5 mg/ml, respectively.GC-MS analysis revealed the typical chemical profiles of the volatile oils. The major component showed the characteristicsof the volatile oils and was probably responsible for the antimicrobial effect.

  19. SYNTHESIS AND ANTIMICROBIAL ACTIVITIES OF NEW PYRAZOLOPYRIDAZINE DERIVATIVES

    Directory of Open Access Journals (Sweden)

    Mahfuz Alam

    2015-03-01

    Full Text Available Several new pryrazolo-pyridazine derivatives (4a-h were synthesized through multi-step synthesis and evaluated for their antimicrobial activities. In the first step, 6-phenyl-2,3,4,5-tetrahydropyridazin-3-one (2 was prepared by reacting 4-(4-chlorophenyl-4-oxobutanoic acid (1 with hydrazine hydrate. Then, aryl-aldehydes were reacted with 2 to furnish pyridazinone derivatives (3a-g. Finally, pyridazinones (3a-h were reacted with hydrazine hydrate to furnish the title compounds (4a-h. The newly synthesized compounds were evaluated for their in vitro antibacterial and antifungal activities against six microbial strains. Compounds 4d, 4e and 4f exhibited significant antibacterial action, whereas compounds 4c and 4d showed potential antifungal activity. Compound 4d, 5-(4-Chlorophenyl-3-(4-fluorophenyl-3,3a,4,7-tetrahydro-2H-pyrazolo[3,4- ]pyridazine, emerged as lead compound having broad spectrum of antimicrobial action.

  20. Insect antimicrobial peptides act synergistically to inhibit a trypanosome parasite.

    Science.gov (United States)

    Marxer, Monika; Vollenweider, Vera; Schmid-Hempel, Paul

    2016-05-26

    The innate immune system provides protection from infection by producing essential effector molecules, such as antimicrobial peptides (AMPs) that possess broad-spectrum activity. This is also the case for bumblebees, Bombus terrestris, when infected by the trypanosome, Crithidia bombi Furthermore, the expressed mixture of AMPs varies with host genetic background and infecting parasite strain (genotype). Here, we used the fact that clones of C. bombi can be cultivated and kept as strains in medium to test the effect of various combinations of AMPs on the growth rate of the parasite. In particular, we used pairwise combinations and a range of physiological concentrations of three AMPs, namely Abaecin, Defensin and Hymenoptaecin, synthetized from the respective genomic sequences. We found that these AMPs indeed suppress the growth of eight different strains of C. bombi, and that combinations of AMPs were typically more effective than the use of a single AMP alone. Furthermore, the most effective combinations were rarely those consisting of maximum concentrations. In addition, the AMP combination treatments revealed parasite strain specificity, such that strains varied in their sensitivity towards the same mixtures. Hence, variable expression of AMPs could be an alternative strategy to combat highly variable infections.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. PMID:27160603

  1. Antimicrobial Peptides as Mediators of Innate Immunity in Teleosts.

    Science.gov (United States)

    Katzenback, Barbara A

    2015-09-25

    Antimicrobial peptides (AMPs) have been identified throughout the metazoa suggesting their evolutionarily conserved nature and their presence in teleosts is no exception. AMPs are short (18-46 amino acids), usually cationic, amphipathic peptides. While AMPs are diverse in amino acid sequence, with no two AMPs being identical, they collectively appear to have conserved functions in the innate immunity of animals towards the pathogens they encounter in their environment. Fish AMPs are upregulated in response to pathogens and appear to have direct broad-spectrum antimicrobial activity towards both human and fish pathogens. However, an emerging role for AMPs as immunomodulatory molecules has become apparent-the ability of AMPs to activate the innate immune system sheds light onto the multifaceted capacity of these small peptides to combat pathogens through direct and indirect means. Herein, this review focuses on the role of teleost AMPs as modulators of the innate immune system and their regulation in response to pathogens or other exogenous molecules. The capacity to regulate AMP expression by exogenous factors may prove useful in modulating AMP expression in fish to prevent disease, particularly in aquaculture settings where crowded conditions and environmental stress pre-dispose these fish to infection.

  2. Comparison of the antibacterial activity of an ozonated oil with chlorhexidine digluconate and povidone-iodine. A disk diffusion test.

    Science.gov (United States)

    Montevecchi, Marco; Dorigo, Antonio; Cricca, Monica; Checchi, Luigi

    2013-07-01

    Ozonated oils are antiseptics obtained from the chemical reaction between ozone and unsaturated fatty acids of vegetable oils. The aim of this study was to investigate the antimicrobial effectiveness of a commercially available ozonated oil (O3-Oil), in comparison with 0.2% chlorhexidine digluconate (CHX) and 10% povidone-iodine (PVP-I) through a disk diffusion test. For each antiseptic a series of two-fold dilutions was made, obtaining seven dilutions: 1:2, 1:4, 1:8, 1:16, 1:32, 1:64 and 1:128. The undiluted antiseptics and the seven dilutions were tested against two freeze-dried bacterial strains: Staphylococcus aureus (Sa) and Porphyromonas gingivalis (Pg). O3-Oil showed significantly greater diameters of growth inhibition (p<0.01) than CHX and PVP-I in all dilutions for both tested strains. CHX lost any antibacterial efficacy when diluted more than 1:32. At the highest dilution, the diameters of growth inhibition against Sa were 20.67±0.58 mm and 15.33±0.58 mm, for O3-Oil and PVP-I, respectively. At the same dilution, the diameters of growth inhibition against Pg were: 19.00 mm for O3-Oil and 13.67±0.58 mm for PVP-I. The promising results obtained for the O3-Oil, against the opportunistic Sa, and Pg, one of the main periodontal pathogens, suggest its potential applicability for periodontal treatment. Further preclinical and clinical investigations are warranted.

  3. Antimicrobial peptides.

    Science.gov (United States)

    Zhang, Ling-Juan; Gallo, Richard L

    2016-01-11

    Antimicrobial peptides and proteins (AMPs) are a diverse class of naturally occurring molecules that are produced as a first line of defense by all multicellular organisms. These proteins can have broad activity to directly kill bacteria, yeasts, fungi, viruses and even cancer cells. Insects and plants primarily deploy AMPs as an antibiotic to protect against potential pathogenic microbes, but microbes also produce AMPs to defend their environmental niche. In higher eukaryotic organisms, AMPs can also be referred to as 'host defense peptides', emphasizing their additional immunomodulatory activities. These activities are diverse, specific to the type of AMP, and include a variety of cytokine and growth factor-like effects that are relevant to normal immune homeostasis. In some instances, the inappropriate expression of AMPs can also induce autoimmune diseases, thus further highlighting the importance of understanding these molecules and their complex activities. This Primer will provide an update of our current understanding of AMPs. PMID:26766224

  4. Chlorhexidine varnishes effectively inhibit Porphyromonas gingivalis and Streptococcus mutans - An in vivo study

    Directory of Open Access Journals (Sweden)

    George Ashwin

    2010-01-01

    Full Text Available Background: Chlorhexidine varnish (Cervitec- Ivoclar Vivadent- Liechtenstein is a sustained-release delivery system that can provide protection against white spots and gingivitis, which are common iatrogenic side effects of orthodontic treatment. Chlorhexidine in varnish form does not depend on patient compliance, does not stain teeth or alter taste sensation like the mouth rinse. Materials and Methods : A split-mouth technique was followed in the treatment of 30 patients selected by stringent selection criteria, evaluating a single application of the test varnish on two randomly allotted quadrants along with a placebo on the other two quadrants. Streptococcus mutans counts responsible for white spots and P. gingivalis count [using PCR test] responsible for gingivitis were done at the start of the study, and then 1 and 3 months later. Results: The chlorhexidine varnish reduced the Streptococci mutans count at the end of 1 month, and this reduction was statistically significant. At the end of 3 months, there was no difference in the S. mutans counts between the two groups. There was a statistically significant reduction in the P. gingivalis count at the end of both 1 and 3 months in comparison to the placebo group. Conclusion: Chlorhexidine varnishes are capable of reducing S. mutans and P. gingivalis and gingivitis, thus improving the overall oral health of the patient. The side effects of chlorhexidine mouth rinses are not seen with this varnish. An application schedule of at least once a month is recommended as the effectiveness is reduced comparatively at the end of 3 months.

  5. Effect of Manuka honey, chlorhexidine gluconate and xylitol on the clinical levels of dental plaque

    Directory of Open Access Journals (Sweden)

    Prathibha A Nayak

    2010-01-01

    Full Text Available Aims: To compare the effect of Manuka honey, chlorhexidine gluconate (0.2% mouthwash and xylitol chewing gum on the dental plaque levels. Materials and Methods: Sixty healthy male dental students aged between 21 and 25 years (mean age 23.4 years participated in the study. All the subjects received a professional prophylaxis at the start of the study, with the purpose of making the dentition 100% free of plaque and calculus. The subjects were then randomly divided into three groups, i.e. the Manuka honey group, the chlorhexidine gluconate mouthwash group and the xylitol chewing gum group. Rinsing with water or any other fluid after the procedure was not allowed as also any form of mechanical oral hygiene for all the subjects during the experimental period of 72 h. After the experimental period, the plaque was disclosed using disclosing solution and their scores were recorded at six sites per tooth using the Quigley and Hein plaque index modified by Turesky-Gilmore-Glickman. Results: The mean plaque scores for Groups I, II and III were 1.37, 1.35 and 1.57, respectively. The ANOVA revealed that between-group comparison was significant, with an F-value of 5.99 and a probability value of 0.004. The T-test was carried out to evaluate the inter-group significance, which revealed that the plaque inhibition by Manuka honey was similar to that of chlorhexidine mouthwash. Both Manuka honey and chlorhexidine mouthwash reduced plaque formation significantly, better than the xylitol chewing gum. Conclusion: Manuka honey and chlorhexidine mouthwash reduced plaque formation significantly better than xylitol chewing gum.

  6. Antimicrobial Peptides as Potential Alternatives to Antibiotics in Food Animal Industry.

    Science.gov (United States)

    Wang, Shuai; Zeng, Xiangfang; Yang, Qing; Qiao, Shiyan

    2016-01-01

    Over the last decade, the rapid emergence of multidrug-resistant pathogens has become a global concern, which has prompted the search for alternative antibacterial agents for use in food animals. Antimicrobial peptides (AMPs), produced by bacteria, insects, amphibians and mammals, as well as by chemical synthesis, are possible candidates for the design of new antimicrobial agents because of their natural antimicrobial properties and a low propensity for development of resistance by microorganisms. This manuscript reviews the current knowledge of the basic biology of AMPs and their applications in non-ruminant nutrition. Antimicrobial peptides not only have broad-spectrum activity against bacteria, fungi, and viruses but also have the ability to bypass the common resistance mechanisms that are placing standard antibiotics in jeopardy. In addition, AMPs have beneficial effects on growth performance, nutrient digestibility, intestinal morphology and gut microbiota in pigs and broilers. Therefore, AMPs have good potential as suitable alternatives to conventional antibiotics used in swine and poultry industries. PMID:27153059

  7. Design of embedded-hybrid antimicrobial peptides with enhanced cell selectivity and anti-biofilm activity.

    Directory of Open Access Journals (Sweden)

    Wei Xu

    Full Text Available Antimicrobial peptides have attracted considerable attention because of their broad-spectrum antimicrobial activity and their low prognostic to induce antibiotic resistance which is the most common source of failure in bacterial infection treatment along with biofilms. The method to design hybrid peptide integrating different functional domains of peptides has many advantages. In this study, we designed an embedded-hybrid peptide R-FV-I16 by replacing a functional defective sequence RR7 with the anti-biofilm sequence FV7 embedded in the middle position of peptide RI16. The results demonstrated that the synthetic hybrid the peptide R-FV-I16 had potent antimicrobial activity over a wide range of Gram-negative and Gram-positive bacteria, as well as anti-biofilm activity. More importantly, R-FV-I16 showed lower hemolytic activity and cytotoxicity. Fluorescent assays demonstrated that R-FV-I16 depolarized the outer and the inner bacterial membranes, while scanning electron microscopy and transmission electron microscopy further indicated that this peptide killed bacterial cells by disrupting the cell membrane, thereby damaging membrane integrity. Results from SEM also provided evidence that R-FV-I16 inherited anti-biofilm activity from the functional peptide sequence FV7. Embedded-hybrid peptides could provide a new pattern for combining different functional domains and showing an effective avenue to screen for novel antimicrobial agents.

  8. Antimicrobial Peptides as Potential Alternatives to Antibiotics in Food Animal Industry

    Directory of Open Access Journals (Sweden)

    Shuai Wang

    2016-05-01

    Full Text Available Over the last decade, the rapid emergence of multidrug-resistant pathogens has become a global concern, which has prompted the search for alternative antibacterial agents for use in food animals. Antimicrobial peptides (AMPs, produced by bacteria, insects, amphibians and mammals, as well as by chemical synthesis, are possible candidates for the design of new antimicrobial agents because of their natural antimicrobial properties and a low propensity for development of resistance by microorganisms. This manuscript reviews the current knowledge of the basic biology of AMPs and their applications in non-ruminant nutrition. Antimicrobial peptides not only have broad-spectrum activity against bacteria, fungi, and viruses but also have the ability to bypass the common resistance mechanisms that are placing standard antibiotics in jeopardy. In addition, AMPs have beneficial effects on growth performance, nutrient digestibility, intestinal morphology and gut microbiota in pigs and broilers. Therefore, AMPs have good potential as suitable alternatives to conventional antibiotics used in swine and poultry industries.

  9. Identification of didecyldimethylammonium salts and salicylic acid as antimicrobial compounds in commercial fermented radish kimchi.

    Science.gov (United States)

    Li, Jing; Chaytor, Jennifer L; Findlay, Brandon; McMullen, Lynn M; Smith, David C; Vederas, John C

    2015-03-25

    Daikon radish (Raphanus sativus) fermented with lactic acid bacteria, especially Leuconostoc or Lactobacillus spp., can be used to make kimchi, a traditional Korean fermented vegetable. Commercial Leuconostoc/radish root ferment filtrates are claimed to have broad spectrum antimicrobial activity. Leuconostoc kimchii fermentation products are patented as preservatives for cosmetics, and certain strains of this organism are reported to produce antimicrobial peptides (bacteriocins). We examined the antimicrobial agents in commercial Leuconostoc/radish root ferment filtrates. Both activity-guided fractionation with Amberlite XAD-16 and direct extraction with ethyl acetate gave salicylic acid as the primary agent with activity against Gram-negative bacteria. Further analysis of the ethyl acetate extract revealed that a didecyldimethylammonium salt was responsible for the Gram-positive activity. The structures of these compounds were confirmed by a combination of (1)H- and (13)C NMR, high-performance liquid chromatography, high-resolution mass spectrometry, and tandem mass spectrometry analyses. Radiocarbon dating indicates that neither compound is a fermentation product. No antimicrobial peptides were detected.

  10. Resistance of Streptococcus sanguis biofilms to antimicrobial agents

    DEFF Research Database (Denmark)

    Larsen, T; Fiehn, N E

    1996-01-01

    Bacteria living in biofilms as dental plaque on tooth surfaces are generally more resistant to antimicrobial agents than bacteria in batch culture normally used for in vitro susceptibility testing. In order to compare the resistance of free-living and surface-grown oral bacteria, the MIC of Strep......Bacteria living in biofilms as dental plaque on tooth surfaces are generally more resistant to antimicrobial agents than bacteria in batch culture normally used for in vitro susceptibility testing. In order to compare the resistance of free-living and surface-grown oral bacteria, the MIC...... of Streptococcus sanguis 804 and ATCC 10556 to amoxicillin, doxycycline and chlorhexidine was determined by a broth dilution method. Subsequently, S. sanguis biofilms established in an in vitro flow model were perfused with the antimicrobial agents for 48 h at concentrations equal to and up to 500 times the MIC......, and biofilm cell number was determined during this period. The antibiotics at the MIC did not affect the cell number of S. sanguis biofilms compared to the starting point, and only after 48 h at 500 times the MIC were the biofilm bacteria eliminated. At intermediate concentrations biofilm cell number...

  11. Comparative assessment of Cranberry and Chlorhexidine mouthwash on streptococcal colonization among dental students: A randomized parallel clinical trial

    Directory of Open Access Journals (Sweden)

    Mahesh R Khairnar

    2015-01-01

    Full Text Available Background: Chlorhexidine gluconate mouthwash has earned an eponym of the gold standard against oral infections, but with certain limitations. There is no effective alternative to Chlorhexidine. Cranberry is known to inhibit bacterial adhesion in various systemic infections and acts as a strong antioxidant. However, it is less explored for its dental use. Hence, there is a need to evaluate its effect against oral infections. Aim: The aim was to compare the efficacy of 0.2% Chlorhexidine mouthwash with 0.6% Cranberry mouthwash on Streptococcus mutans. Materials and Methods: This was a double-blind, randomized parallel group clinical trial. Total sample of 50 subjects, aged 18-20 years, were randomly divided into two groups, Group A (25 and Group B (25 were given 10 mL of Chlorhexidine mouthwash and Cranberry mouthwash twice daily, respectively, for 14 days each. The plaque samples, which were taken from the subjects on 1 st day and 14 th day, were inoculated on blood agar plates and incubated at 37΀C for 24-48 h. Number of streptococcal colony forming units were calculated using digital colony counter. The data were subjected to paired t-test and unpaired t-test at a 5% significance level. Results: (1 Chlorhexidine mouthwash showed 69% reduction whereas Cranberry mouthwash showed 68% reduction in S. mutans count. (2 No significant difference was seen between Chlorhexidine and Cranberry mouthwash on streptococci. Conclusion: Cranberry mouthwash is equally effective as Chlorhexidine mouthwash with beneficial local and systemic effect. Hence, it can be used effectively as an alternative to Chlorhexidine mouthwash.

  12. Impact of chlorhexidine mouthwash prophylaxis on probable ventilator-associated pneumonia in a surgical intensive care unit

    OpenAIRE

    Enwere, Emmanuel N; Elofson, Kathryn A; Forbes, Rachel C.; Gerlach, Anthony T

    2016-01-01

    Background: Prevention of ventilator-associated pneumonia is a healthcare goal. Although data is inconsistent, some studies suggest that oral chlorhexidine may decrease rates of pneumonia in mechanically-ventilated patients. We sought to assess the rate of pneumonia in the Surgical Intensive Care Unit (SICU) pre and post implementation of routine chlorhexidine mouthwash prophylaxis. Materials and Methods: A retrospective cohort study was conducted, including patients between 1/1/2009 and 12/3...

  13. Cytotoxicity of chlorhexidine digluconate to murine macrophages and its effect on hydrogen peroxide and nitric oxide induction

    OpenAIRE

    Bonacorsi C.; Raddi M.S.G.; Carlos I.Z.

    2004-01-01

    Chlorhexidine, even at low concentrations, is toxic for a variety of eukaryotic cells; however, its effects on host immune cells are not well known. We evaluated in vitro chlorhexidine-induced cytotoxicity and its effects on reactive oxygen/nitrogen intermediate induction by murine peritoneal macrophages. Thioglycollate-induced cells were obtained from Swiss mice by peritoneal lavage with 5 ml of 10 mM phosphate-buffered saline, washed twice and resuspended (10(6) cells/ml) in appropriate med...

  14. In vitro assessment of the antimicrobial effects of pomegranate (Punica granatum L. peel decoction on saliva samples

    Directory of Open Access Journals (Sweden)

    Solon José de Oliveira Leite

    2014-01-01

    Full Text Available Several products have been developed to eliminate or reduce potential pathogenic microorganisms of the oral microbiome. The continuous use of these synthetic products can result in side effects such as vomiting, diarrhea, darkening of the teeth and the induction of microbial resistance. Pomegranate (Punica granatum peel decoction was tested to assess its antimicrobial activity. In vitro analysis showed the decoction had antimicrobial activity against strains of Pseudomonas aeruginosa and Candida albicans, but none was detected against Enterococcus faecalis. When tested on saliva samples from children, the decoction showed great potential in reducing the load of microorganisms, the inhibition haloes produced with saliva samples being similar to those of the antimicrobial control (0.12% chlorhexidine. The pomegranate peel decoction in water could thus provide a promising source for developing solutions for use against oral diseases.

  15. Antimicrobials Influence Bond Stiffness and Detachment of Oral Bacteria.

    Science.gov (United States)

    Song, L; Hou, J; van der Mei, H C; Veeregowda, D H; Busscher, H J; Sjollema, J

    2016-07-01

    Oral biofilm can never be fully removed by oral hygiene measures. Biofilm left behind after brushing is often left behind on the same sites and exposed multiple times to antimicrobials from toothpastes and mouthrinses, after which removal becomes increasingly difficult. On the basis of this observation, we hypothesize that oral bacteria adhering to salivary conditioning films become more difficult to remove after adsorption of antimicrobials due to stiffening of their adhesive bond. To verify this hypothesis, bacteria adhering to bare and saliva-coated glass were exposed to 3 different mouthrinses, containing chlorhexidine-digluconate, cetylpyridinium-chloride, or amine-fluoride, after which bacterial vibration spectroscopy was carried out or a liquid-air interface was passed over the adhering bacteria to stimulate their detachment. Brownian motion-induced nanoscopic vibration amplitudes of 4 oral streptococcal strains, reflecting their bond stiffness, decreased after exposure to mouthrinses. Concurrently, the percentage detachment of adhering bacteria upon the passage of a liquid-air interface decreased after exposure to mouthrinses. A buffer control left both vibration amplitudes and detachment percentages unaffected. Exposure to either of the selected mouthrinses yielded more positively charged bacteria by particulate microelectrophoresis, suggesting antimicrobial adsorption to bacterial cell surface components. To rule out that exposure of adhering bacteria to the mouthrinses stimulated polysaccharide production with an impact on their detachment, Fourier transform infrared spectroscopy was carried out on bacteria adhering to an internal reflection element, prior to and after exposure to the mouthrinses. Infrared absorption band areas indicated no significant change in amount of polysaccharides after exposure of adhering bacteria to mouthrinses, but wave number shifts demonstrated stiffening of polysaccharides in the bond, as a result of antimicrobial

  16. Mucin biopolymers as broad-spectrum antiviral agents

    Science.gov (United States)

    Lieleg, Oliver; Lieleg, Corinna; Bloom, Jesse; Buck, Christopher B.; Ribbeck, Katharina

    2012-01-01

    Mucus is a porous biopolymer matrix that coats all wet epithelia in the human body and serves as the first line of defense against many pathogenic bacteria and viruses. However, under certain conditions viruses are able to penetrate this infection barrier, which compromises the protective function of native mucus. Here, we find that isolated porcine gastric mucin polymers, key structural components of native mucus, can protect an underlying cell layer from infection by small viruses such as human papillomavirus (HPV), Merkel cell polyomavirus (MCV), or a strain of influenza A virus. Single particle analysis of virus mobility inside the mucin barrier reveals that this shielding effect is in part based on a retardation of virus diffusion inside the biopolymer matrix. Our findings suggest that purified mucins may be used as a broad-range antiviral supplement to personal hygiene products, baby formula or lubricants to support our immune system. PMID:22475261

  17. Enhanced methanol production in plants provides broad spectrum insect resistance.

    Directory of Open Access Journals (Sweden)

    Sameer Dixit

    Full Text Available Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR and spectra showed up to 16 fold higher methanol as compared to control wild type (WT plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid and Bemisia tabaci (whitefly, respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants.

  18. Identification of Ebsulfur Analogues with Broad-Spectrum Antifungal Activity.

    Science.gov (United States)

    Ngo, Huy X; Shrestha, Sanjib K; Garneau-Tsodikova, Sylvie

    2016-07-19

    Invasive fungal infections are on the rise due to an increased population of critically ill patients as a result of HIV infections, chemotherapies, and organ transplantations. Current antifungal drugs are helpful, but are insufficient in addressing the problem of drug-resistant fungal infections. Thus, there is a growing need for novel antimycotics that are safe and effective. The ebselen scaffold has been evaluated in clinical trials and has been shown to be safe in humans. This makes ebselen an attractive scaffold for facile translation from bench to bedside. We recently reported a library of ebselen-inspired ebsulfur analogues with antibacterial properties, but their antifungal activity has not been characterized. In this study, we repurposed ebselen, ebsulfur, and 32 additional ebsulfur analogues as antifungal agents by evaluating their antifungal activity against a panel of 13 clinically relevant fungal strains. The effect of induction of reactive oxygen species (ROS) by three of these compounds was evaluated. Their hemolytic and cytotoxicity activities were also determined using mouse erythrocytes and mammalian cells. The MIC values of these compounds were found to be in the range of 0.02-12.5 μg mL(-1) against the fungal strains tested. Notably, yeast cells treated with our compounds showed an accumulation of ROS, which may further contribute to the growth-inhibitory effect against fungi. This study provides new lead compounds for the development of antimycotic agents. PMID:27334363

  19. Silver nanoparticles are broad-spectrum bactericidal and virucidal compounds

    Directory of Open Access Journals (Sweden)

    Ixtepan-Turrent Liliana

    2011-08-01

    Full Text Available Abstract The advance in nanotechnology has enabled us to utilize particles in the size of the nanoscale. This has created new therapeutic horizons, and in the case of silver, the currently available data only reveals the surface of the potential benefits and the wide range of applications. Interactions between viral biomolecules and silver nanoparticles suggest that the use of nanosystems may contribute importantly for the enhancement of current prevention of infection and antiviral therapies. Recently, it has been suggested that silver nanoparticles (AgNPs bind with external membrane of lipid enveloped virus to prevent the infection. Nevertheless, the interaction of AgNPs with viruses is a largely unexplored field. AgNPs has been studied particularly on HIV where it was demonstrated the mechanism of antiviral action of the nanoparticles as well as the inhibition the transmission of HIV-1 infection in human cervix organ culture. This review discusses recent advances in the understanding of the biocidal mechanisms of action of silver Nanoparticles.

  20. The broad spectrum of celiac disease and gluten sensitive enteropathy.

    Science.gov (United States)

    Mocan, Oana; Dumitraşcu, Dan L

    2016-01-01

    The celiac disease is an immune chronic condition with genetic transmission, caused by the intolerance to gluten. Gluten is a protein from cereals containing the following soluble proteins: gliadine, which is the most toxic, and the prolamins. The average prevalence is about 1% in USA and Europe, but high in Africa: 5.6% in West Sahara. In the pathogenesis several factors are involved: gluten as external trigger, genetic predisposition (HLA, MYO9B), viral infections, abnormal immune reaction to gluten. Severity is correlated with the number of intraepithelial lymphocytes, cryptic hyperplasia and villous atrophy, as well as with the length of intestinal involvement. The severity is assessed according to the Marsh-Oberhuber staging. Diagnostic criteria are: positive serological tests, intestinal biopsy, the reversal after gluten free diet (GFD). Beside refractory forms, new conditions have been described, like the non celiac gluten intolerance. In a time when more and more people adhere to GFD for nonscientific reasons, practitioners should be updated with the progress in celiac disease knowledge. PMID:27547052