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Sample records for bactericides

  1. Serum bactericidal test.

    OpenAIRE

    Stratton, C W

    1988-01-01

    The serum bactericidal test represents one of the few in vitro tests performed in the clinical microbiology laboratory that combines the interaction of the pathogen, the antimicrobial agent, and the patient. Although the use of such a test antedates the antimicrobial era, its performance, results, and interpretation have been subject to question and controversy. Much of the confusion concerning the serum bactericidal test can be avoided by an understanding of the various factors which influen...

  2. Bactericidal block copolymer micelles.

    Science.gov (United States)

    Vyhnalkova, Renata; Eisenberg, Adi; van de Ven, Theo

    2011-05-12

    Block copolymer micelles with bactericidal properties were designed to deactivate pathogens such as E. coli bacteria. The micelles of PS-b-PAA and PS-b-P4VP block copolymers were loaded with biocides TCMTB or TCN up to 20 or 30 wt.-%, depending on the type of antibacterial agent. Bacteria were exposed to loaded micelles and bacterial deactivation was evaluated. The micelles loaded with TCN are bactericidal; bacteria are killed in less than two minutes of exposure. The most likely interpretation of the data is that the biocide is transferred to the bacteria by repeated micelle/bacteria contacts, and not via the solution. PMID:21275041

  3. Bactericidal properties of pradofloxacin against veterinary pathogens.

    Science.gov (United States)

    Silley, Peter; Stephan, Bernd; Greife, Heinrich A; Pridmore, Andrew

    2012-05-25

    Pradofloxacin is a new veterinary 8-cyano-fluoroquinolone developed for use against bacterial infections in dogs and cats involving both aerobic and anaerobic bacteria. The minimal bactericidal concentrations have been determined against clinical isolates of Staphylococcus pseudintermedius, Staphylococcus aureus, Escherichia coli, Pasteurella multocida, Streptococcus canis, Proteus spp., Fusobacterium spp., Porphyromonas gingivalis and Prevotella species. A subset of these species was selected, and the in vitro rate of kill by pradofloxacin was determined. For 27 of the 30 tested aerobic strains the pradofloxacin MBC was within two doubling dilutions of the MIC. For the remaining strains, the MIC and MBC were within three to four doubling dilutions. Pradofloxacin also demonstrated bactericidal activity against all anaerobic strains, and the MBC was equal to the MIC for four of the strains, within 1 doubling dilution for three strains, within 2 dilutions for a further 3 strains and within 3 dilutions for the remaining five strains. As pradofloxacin concentration was increased, a faster rate of killing was observed; bactericidal effects were seen in all cases at concentrations ≤ 0.25 μg/mL. The bactericidal activity against the anaerobic strains was marked, of particular relevance was the complete absence of regrowth even at 48 h at concentrations as low as 0.125 μg/mL. In conclusion, pradofloxacin exhibits clear bactericidal activity in terms of MBC and kill kinetics against aerobic and anaerobic clinical isolates from dogs and cats at concentrations that are greatly exceeded within the systemic circulation after administration of the recommended therapeutic doses to the target animals. It is expected that such a rapid rate of kill will play a significant role in clinical efficacy. These data demonstrate the complete and rapid killing of anaerobic bacteria by a veterinary 8-cyano-fluoroquinolone. PMID:22209121

  4. Electrospun biodegradable polymers loaded with bactericide agents

    Directory of Open Access Journals (Sweden)

    Ramaz Katsarava

    2016-03-01

    Full Text Available Development of materials with an antimicrobial activity is fundamental for different sectors, including medicine and health care, water and air treatment, and food packaging. Electrospinning is a versatile and economic technique that allows the incorporation of different natural, industrial, and clinical agents into a wide variety of polymers and blends in the form of micro/nanofibers. Furthermore, the technique is versatile since different constructs (e.g. those derived from single electrospinning, co-electrospinning, coaxial electrospinning, and miniemulsion electrospinning can be obtained to influence the ability to load agents with different characteristics and stability and to modify the release behaviour. Furthermore, antimicrobial agents can be loaded during the electrospinning process or by a subsequent coating process. In order to the mitigate burst release effect, it is possible to encapsulate the selected drug into inorganic nanotubes and nanoparticles, as well as in organic cyclodextrine polysaccharides. In the same way, processes that involve covalent linkage of bactericide agents during surface treatment of electrospun samples may also be considered. The present review is focused on more recent works concerning the electrospinning of antimicrobial polymers. These include chitosan and common biodegradable polymers with activity caused by the specific load of agents such as metal and metal oxide particles, quaternary ammonium compounds, hydantoin compounds, antibiotics, common organic bactericides, and bacteriophages.

  5. Tolerance of staphylococci to bactericidal antibiotics.

    Science.gov (United States)

    Vaudaux, Pierre; Lew, Daniel P

    2006-05-01

    Antibiotic therapy for deep-seated staphylococcal infections, especially when they are associated with artificial devices used for orthopedic surgery is often associated with failure. Standard anti-staphylococcal bactericidal antibiotics, such as semi-synthetic penicillins, cephalosporins, or glycopeptides, are effective when given prophylactically in clinical conditions or experimental trials of implant-related infections. However, the efficacy of all anti-staphylococcal agents is seriously diminished on already established implant-related deep-seated infections, which then frequently require surgical implant removal to obtain a cure. The failure of antibiotic therapy to cure established staphylococcal foreign-body infections may arise in part from a broad-spectrum phenotypic tolerance expressed in vivo to different classes of antimicrobial agents. The molecular and physiological mechanisms of this in vivo tolerance remain poorly understood. PMID:16651066

  6. Hierarchical polymer coating for optimizing the antifouling and bactericidal efficacies.

    Science.gov (United States)

    Yan, Shunjie; Song, Lingjie; Li, Zhihong; Luan, Shifang; Shi, Hengchong; Xin, Zhirong; Li, Shenghai; Yang, Yuming; Yin, Jinghua

    2016-10-01

    The bacteria-repellent and bactericidal functionalities in a single system are generally need to be carefully optimized in order to obtain the highest antibacterial performance. In this study, the controlled SI-PIMP strategy was developed for creating hierarchical polymer brushes possessing the bacteria-repellent and bactericidal functionalities. To obtain a bactericidal surface with minimal interference to its nonfouling property, optimization studies were conducted by facilely tailoring the surface density of the quaternary ammonium compound moieties through control over the monomer concentration. An optimal hierarchical polymer coating showed potent protein and bacteria repellence as well as certain bactericidal property. The longlasting antibacterial performance was also achieved due to the good balance between the dual functionalities. The tenability of the hierarchical polymer coating is applicable to surface chemistries for biosensors, molecular imaging, and biomedical applications. PMID:27363527

  7. The bactericidal effect of a Genius (R) Nd : YAG laser

    NARCIS (Netherlands)

    Kranendonk, A.A.; Reijden, W.A. van der; Winkelhoff, A.J. van; Weijden, G.A. van der

    2010-01-01

    PURPOSE: To evaluate the 'in vitro' bactericidal effect of the Nd:YAG laser (Genius, MØlsgaard Dental, Copenhagen, Denmark) on six periodontal pathogens. METHODS: Suspensions of six different periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedi

  8. Two major medicinal honeys have different mechanisms of bactericidal activity.

    Directory of Open Access Journals (Sweden)

    Paulus H S Kwakman

    Full Text Available Honey is increasingly valued for its antibacterial activity, but knowledge regarding the mechanism of action is still incomplete. We assessed the bactericidal activity and mechanism of action of Revamil® source (RS honey and manuka honey, the sources of two major medical-grade honeys. RS honey killed Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa within 2 hours, whereas manuka honey had such rapid activity only against B. subtilis. After 24 hours of incubation, both honeys killed all tested bacteria, including methicillin-resistant Staphylococcus aureus, but manuka honey retained activity up to higher dilutions than RS honey. Bee defensin-1 and H₂O₂ were the major factors involved in rapid bactericidal activity of RS honey. These factors were absent in manuka honey, but this honey contained 44-fold higher concentrations of methylglyoxal than RS honey. Methylglyoxal was a major bactericidal factor in manuka honey, but after neutralization of this compound manuka honey retained bactericidal activity due to several unknown factors. RS and manuka honey have highly distinct compositions of bactericidal factors, resulting in large differences in bactericidal activity.

  9. Study of Bactericidal Properties of Propolis

    Directory of Open Access Journals (Sweden)

    Daniela Marina Mot

    2014-05-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE The antibacterial activity of an alcoholic extract of propolis from Apis mellifera was investigated using a method of growth inhibition in the culture medium of microorganisms. For this study were been chosen bacterial species implicated in severe infections in animals: Streptococcus suis, Staphylococcus aureus, Escherichia coli, Salmonella spp., Pseudomonas aeruginosa and Pasteurella haemolytica (Mannheimia haemolytica, 1999. The propolis extract demonstrated to possess bactericidal properties against studied microorganisms in descending order as follows: Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Streptococcus pyogenes, Pasteurella haemolytica, Salmonella spp. All these results demonstrates the possibility of using propolis in either treatment alone, as a natural alternative, be associated with an appropriate antibiotic for the potentiation effect in the event of serious infections in animals. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;}

  10. Bacteriostatic and Bactericidal Activities of Moxifloxacin against Coxiella burnetii

    OpenAIRE

    Rolain, Jean-Marc; Maurin, Max; Raoult, Didier

    2001-01-01

    The in vitro activity of moxifloxacin against Coxiella burnetii was compared to those of pefloxacin, ofloxacin, and doxycycline. MICs of moxifloxacin ranged from 0.5 to 1 μg/ml for the Nine Mile, Priscilla, and Q212 strains. Moxifloxacin was not bactericidal against C. burnetii at 4 μg/ml.

  11. Studies on bactericidal efficacy of pumpkin (Cucurbita moschata Duchesne) peel

    Institute of Scientific and Technical Information of China (English)

    El Zawane Kamarudin; Qamar Uddin Ahmed; Zuvairea Nazren Mohd Sirajudin; Ahmad Jalal Khan Chowdhury

    2014-01-01

    Objective: To explore the in vitro antibacterial potential of the peel of Cucurbita moschata Duchesne (tropical pumpkin) (C. moschata) against human pathogenic bacteria. Methods:In the present study, dichloromethane (DCM), methanol (MEOH) and aqueous extracts of C. moschata peel were examined for in vitro antibacterial potency against eight bacterial strains i.e. Bacillus cereus, Burkholderia cepacia, Escherichia coli, Enterococcus faecalis, Staphyloccocus aureus, Pseudomonas aerugenosa, Vibrio alginolyticus, Vibrio parahaemolyticus using Kirby-Bauer disk diffusion susceptibility and broth micro-dilution methods. Results: DCM extract of pumpkin peel exhibited the maximum zone of inhibition against Staphyloccocus aureus (21 mm) whereas aqueous extract of pumpkin peel revealed the least zone of inhibition against Escherichia coli (8 mm). MEOH extract gave maximum zone of inhibition against Pseudomonas aerugenosa (19 mm). Broth micro-dilution method showed minimum inhibitory concentration for the DCM extract against Burkholderia cepacia at 6.25 mg/mL. The minimum bactericidal concentrations were also determined to know the nature of all extracts. DCM and MEOH extracts exhibited bactericidal nature to all bacterial strains except for the Vibrio alginolyticus. The minimum bactericidal concentrations values exhibited bactericidal nature ranging from 3.12 mg/mL to 100.00 mg/mL. The screening of antimicrobial properties of different extracts of C. moschata peel revealed that the DCM extract possessed good antimicrobial efficacy compared to MEOH and aqueous extracts. Conclusions: Peel of C. moschata possesses antibacterial compounds and could be potential source for a new class of antibiotics.

  12. Bactericidal action of cold atmospheric plasma in solution

    International Nuclear Information System (INIS)

    In this study different influences on the bactericidal effect of cold atmospheric plasma (CAP) were investigated intensively. In detail, different initial densities of Escherichia coli cells and different treatment times of up to 8 min were studied. The results show that up to densities of 105 cells per 20 μl high reduction rates of up to 5 log can be achieved in less than 3 min of CAP application. In contrast, for higher cell densities almost no reduction was measured for CAP treatment times of up to 8 min. To understand this data in detail, a theoretical model was developed. This model starts from the premise that bacteria are able to some degree to neutralize reactive species and that accordingly the bactericidal effect depends on the bacterial concentration. A further purpose of this study was to analyze the contribution of reactive oxygen and also reactive nitrogen species—produced by the CAP—to the bactericidal effect. We therefore measured nitrites, nitrates and hydrogen peroxide—products of chemical reactions between the species produced by the CAP and the liquid. The evidence of nitric oxide (NO) uptake in bacteria and the corresponding reference experiments with hydrogen peroxide and a chemical NO donor clearly show that the bactericidal effect of CAP is related to a combination of oxidative and nitrosative effects. (paper)

  13. Studies on bactericidal efficacy of pumpkin (Cucurbita moschata Duchesne peel

    Directory of Open Access Journals (Sweden)

    El Zawane Kamarudin

    2014-02-01

    Full Text Available Objective: T o explore the in vitro antibacterial potential of the peel of Cucurbita moschata D uchesne ( tropical pumpkin ( C. moschata against human pathogenic bacteria. Methods: I n the present study, dichloromethane ( DCM , methanol ( MEOH and aqueous extracts of C. moschata peel were examined for in vitro antibacterial potency against eight bacterial strains i.e. Bacillus cereus, Burkholderia cepacia, Escherichia coli, Enterococcus faecalis, Staphyloccocus aureus, Pseudomonas aerugenosa, Vibrio alginolyticus, Vibrio parahaemolyticus using K irby- B auer disk diffusion susceptibility and broth micro-dilution methods. Results: DCM extract of pumpkin peel exhibited the maximum zone of inhibition against Staphyloccocus aureus ( 21 mm whereas aqueous extract of pumpkin peel revealed the least zone of inhibition against Escherichia coli ( 8 mm . MEOH extract gave maximum zone of inhibition against Pseudomonas aerugenosa ( 19 mm . B roth micro-dilution method showed minimum inhibitory concentration for the DCM extract against Burkholderia cepacia at 6 . 25 mg/m L . T he minimum bactericidal concentrations were also determined to know the nature of all extracts. DCM and MEOH extracts exhibited bactericidal nature to all bacterial strains except for the Vibrio alginolyticus. T he minimum bactericidal concentrations values exhibited bactericidal nature ranging from 3 . 12 mg/m L to 100 . 00 mg/m L . T he screening of antimicrobial properties of different extracts of C. moschata peel revealed that the DCM extract possessed good antimicrobial efficacy compared to MEOH and aqueous extracts. Conclusions: P eel of C. moschata possesses antibacterial compounds and could be potential source for a new class of antibiotics.

  14. Improved bactericidal enzybiotics against pneumococcus and other bacteria

    OpenAIRE

    García González, Pedro; Menéndez Fernández, Margarita; García, Ernesto; Díez-Martínez, Roberto; Paz Fernández, Héctor de; Bustamante, Noemí

    2014-01-01

    [EN] The invention relates to the field of biotechnology and concerns a polypeptide sequence derived from the Cp7 phage lytic enzyme wall-binding module (Cpl-7), which enables new lytic enzymes having improved bactericidal activity and a broad spectrum to be built. The invention also concerns chimeric enzymes containing the improved wall-binding module, and examples of the activity thereof against gram positive and gram negative species are provided.

  15. Powerful Bactericidal Activity of Moxifloxacin in Human Leprosy▿

    OpenAIRE

    Pardillo, Fe Eleanor F.; Burgos, Jasmin; Fajardo, Tranquilino T.; Cruz, Eduardo Dela; Abalos, Rodolfo M.; Paredes, Rose Maria D.; Andaya, Cora Evelyn S.; Gelber, Robert H.

    2008-01-01

    In a clinical trial of moxifloxacin in eight multibacillary leprosy patients, moxifloxacin proved highly effective. In all trial patients, a single 400-mg dose of moxifloxacin resulted in significant killing (P ≤ 0.006) of Mycobacterium leprae, ranging from 82% to 99%, with a mean of 91%. In all instances, no viable bacilli were detected with an additional 3 weeks of daily therapy, this observed rapid bactericidal activity being matched previously only by rifampin. On moxifloxacin therapy, sk...

  16. The bactericidal activity of glutaraldehyde-impregnated polyurethane

    OpenAIRE

    Allan, E.; Sehmi, S.; Parkin, I.; MacRobert, A.

    2016-01-01

    Although glutaraldehyde is known to be bactericidal in solution, its potential use to create novel antibacterial polymers suitable for use in healthcare environments has not been evaluated. Here, novel materials were prepared in which glutaraldehyde was either incorporated into polyurethane using a simple “swell-encapsulation-shrink” method (hereafter referred to as “glutaraldehyde-impregnated polyurethane”), or simply applied to the polymer surface (hereafter referred to as “glutaraldehyde-c...

  17. Bactericidal and cytotoxic effects of hypothiocyanite-hydrogen peroxide mixtures.

    OpenAIRE

    Carlsson, J.; Edlund, M B; Hänström, L.

    1984-01-01

    Lactoperoxidase catalyzes the oxidation of thiocyanate by hydrogen peroxide into hypothiocyanite, a reaction which can protect bacterial and mammalian cells from killing by hydrogen peroxide. The present study demonstrates, however, that lactoperoxidase in the presence of thiocyanate can actually potentiate the bactericidal and cytotoxic effects of hydrogen peroxide under specific conditions, such as when hydrogen peroxide is present in the reaction mixtures in excess of thiocyanate. The toxi...

  18. Rapid infrared determination of the potency of chlorinated bactericides.

    Science.gov (United States)

    Spagnolo, F; Cestaro, J P

    1971-06-01

    A rapid infrared reflectance method for evaluating the germicidal potency of synthetic materials containing various amounts of two chlorinated bactericides was developed. The dimeric product 2,2'-methylenebis (4,6-dichlorophenol) exhibited a characteristic C=C skeletal inplane stretching infrared absorption band at 1,640 cm(-1). The monomeric 2,4-dichlorophenol precursor showed a characteristic absorption band at 1,579 cm(-1). These characteristic infrared absorptions may be used for analysis of the potency of the manufactured chlorinated bactericide. For a series of samples known to vary in dimer content, the micrograms per milliliter required for a 100% bacterial kill is first determined by a standard American Petroleum Institute method. Then the area ratio of the infrared absorption bands characteristic of the chlorinated bactericides is measured for each sample and plotted versus the microgram per milliliter required for 100% bacterial kill. The potency of subsequent samples is simply and rapidly determined by measuring this ratio from the infrared absorption curve and calculating micrograms per milliliter required for 100% kill from the calibration curve. Analysis time is approximately 1 hr compared to biocidal tests in current use requiring approximately a 1-month incubation period. PMID:5564677

  19. Complement-mediated killing of Borrelia garinii--bactericidal activity of wild deer serum.

    Science.gov (United States)

    Isogai, E; Kamewaka, Y; Isogai, H; Kimura, K; Fujii, N; Nishikawa, T

    1994-01-01

    The susceptibility of Borrelia garinii to fresh wild deer sera was determined by incubating strain SIKA2 at 10% serum concentration for 1 hr at 37 C in an in vitro bactericidal assay. Each serum showed bactericidal effects at various levels. The effect was dependent on the concentration of antibody to the spirochetes. Complement was essential in the bactericidal assay because the inactivated deer serum showed greatly decreased activity. Our results suggest that B. garinii is sensitive to deer serum, in the presence of antibody and the bactericidal effect is important for preventing Lyme disease in wild sika deer. PMID:7854216

  20. Natural and Environment-friendly New Bactericide for Leather Industry: Essential Oil of Origanum minutiflorum

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    E. Eser Eke Bayramoglu

    2005-01-01

    Full Text Available In this study, essential oil of Origanum minutiflorum was purchased and used as a bactericide during soaking process to avoid bacterial growth. One gram per liter of oil was applied and also commercial bactericide which is commonly used in leather industry, 7-25% phenol, 4-chloro-3-methyl was used and compared. The trials showed that Origanum minutiflorum has much better antibacterial effect than commercial bactericide. From the study it was concluded that this essential oil can be used as bactericide in leather industry.

  1. The bactericidal and biocompatible characteristics of reinforced calcium phosphate cements

    International Nuclear Information System (INIS)

    Infection remains a serious medical problem in orthopaedic surgery. Antibiotic administration can be available either systemically via the blood stream or locally, directly into the infected bone. One of the main limitations of antibiotic administration is the development of multi-antibiotic-resistant bacterial strains. In this study, we developed bactericidal calcium phosphate cements (CPC) by incorporation of different molecular weight chitosan and hydroxypropyltrimethyl ammonium chloride chitosan (HACC). Two standard strains, S. epidermidis (ATCC35984) and S. aureus (ATCC25923), and one clinical isolate, methicillin-resistant S. epidermidis (MRSE), were selected to evaluate the antibacterial activity of these bone cements. Our data showed that the CPC loaded with low molecular weight chitosan and HACC significantly inhibited the bacterial adhesion and biofilm formation. In addition, HACC-containing CPC has no cytotoxic effects on both mouse pluripotent C3H10T1/2cell line and a murine L929 fibroblast cell line. We propose that HACC-containing CPC represents a promising polymer-based bactericidal bone scaffold in controlling orthopaedic surgery-related infection. (paper)

  2. Bactericidal activity of metal-mediated peroxide-ascorbate systems.

    Science.gov (United States)

    Drath, D B; Karnovsky, M L

    1974-11-01

    Model systems containing ascorbate, hydrogen peroxide, and divalent copper or cobalt have been shown to possess marked bactericidal activity. At equivalent concentrations, copper-containing systems were more bactericidal than the corresponding mixtures containing cobalt. Cobalt at concentrations below 10(-4) M did not appreciably augment microbicidal activity, whereas systems containing copper at concentrations as low as 5 x 10(-6) M were still capable of causing some bacterial death. Manganese was inactive. None of these systems was as potent as the well known myeloperoxidase-peroxide-halide system. The mechanisms of action of these systems are not as yet clear. The possibility that they function through the generation of superoxide (O(2) (-)), hydroxyl radical (OH.), or other free radicals was explored through the use of superoxide dismutase and several free radical scavengers. It seems likely at present that the two active metal-mediated systems function via separate mechanisms. The copper system acts with dehydroascorbate, whereas the cobalt system does not. Activity in the cobalt system appears to depend upon the generation of free radicals. PMID:16558093

  3. Bactericidal behavior of Cu-containing stainless steel surfaces

    Science.gov (United States)

    Zhang, Xiangyu; Huang, Xiaobo; Ma, Yong; Lin, Naiming; Fan, Ailan; Tang, Bin

    2012-10-01

    Stainless steels are one of the most common materials used in health care environments. However, the lack of antibacterial advantage has limited their use in practical application. In this paper, antibacterial stainless steel surfaces with different Cu contents have been prepared by plasma surface alloying technology (PSAT). The steel surface with Cu content 90 wt.% (Cu-SS) exhibits strong bactericidal activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) within 3 h. Although the Cu-containing surface with Cu content 2.5 wt.% (CuNi-SS) can also kill all tested bacteria, this process needs 12 h. SEM observation of the bacterial morphology and an agarose gel electrophoresis were performed to study the antibacterial mechanism of Cu-containing stainless steel surfaces against E. coli. The results indicated that Cu ions are released when the Cu-containing surfaces are in contact with bacterial and disrupt the cell membranes, killing the bacteria. The toxicity of Cu-alloyed surfaces does not cause damage to the bacterial DNA. These results provide a scientific explanation for the antimicrobial applications of Cu-containing stainless steel. The surfaces with different antibacterial abilities could be used as hygienic surfaces in healthcare-associated settings according to the diverse requirement of bactericidal activities.

  4. Serum Bactericidal Assay: New Role in Salmonella Detection.

    Science.gov (United States)

    Chen, Yu; Wu, Da; Sun, Min; Deng, Mingjun; Cui, Shuhua; Liang, Chengzhu; Geng, Juan; Sun, Tao; Long, Ling; Xiao, Xizhi

    2016-01-01

    While inspecting animal feed for Salmonella contamination, we routinely observed bacterial colonies on selective agars that were similar in appearance to those formed by Salmonella. These were identified as Citrobacter freundii, Proteus mirabilis, and Serratia fonticola using biochemical and serological techniques. Because the presence of these bacterial species confounds identification of Salmonella, we refer to them as "interference bacteria." Polyvalent antisera against these interference bacteria were prepared by immunizing rabbits with a mixture of all three organisms. To minimize or eliminate interference by these bacteria, the polyvalent antisera were introduced between the steps of selective enrichment and Salmonella-selective plating. The antisera raised against the interference bacteria, when combined with neonatal rabbit complement, exhibited specific bactericidal activity against C. freundii, P. mirabilis, and S. fonticola. The respective serum bactericidal assay titers were 2(9), 2(8), and 2(10). In selective broth, polyvalent antisera could also kill the target bacterial cells effectively. We tested 526 samples (186 white fishmeal, 97 red fishmeal, and 243 cattle bone powder) using the polyvalent antisera and found that the rates of contamination of each species of the three respective foods decreased by 58.8, 100, and 83%. Our data indicates that polyvalent sera against C. freundii, P. mirabilis, and S. fonticola can be used as inhibitors to increase the accuracy of Salmonella detection. PMID:26822285

  5. Test industrial pumping of an oil displacement bactericide at the Neftyannyye Kamni deposit

    Energy Technology Data Exchange (ETDEWEB)

    Suleymanov, A.B.; Amirov, G.B.; Kandinskaya, L.I.; Kerimov, K.S.; Mamedov, E.A.; Mamedov, N.G.; Pashayev, N.G.

    1983-01-01

    The results are cited of works conducted to increase the oil production of the stratum at the Neftyannyye Kamni deposit through pumping an oil displacement bactericide (BNV), and the issues for selecting an object and process technology for the successful introduction of flooding with the oil displacement bactericide are discussed.

  6. Bactericidal synergy of lysostaphin in combination with antimicrobial peptides.

    Science.gov (United States)

    Desbois, A P; Coote, P J

    2011-08-01

    Drug-resistant staphylococci constitute a serious problem that urgently requires the discovery of new therapeutic agents. There has been a resurgence in interest in using lysostaphin (a specific anti-staphylococcal enzyme) as a treatment for infections caused by these important pathogens. However, bacterial resistance to lysostaphin is a problem, but the use of a combination treatment may surmount this issue. In this present study, using viable counts from suspension incubations, lysostaphin is shown to be synergistically bactericidal in combination with various conventional antimicrobial peptides, the antimicrobial protein bovine lactoferrin, a lantibiotic (nisin), and certain lipopeptides used clinically (colistin, daptomycin and polymyxin B). Combinations that act in synergy are of clinical importance as these reduce the doses of the compounds needed for effective treatments and decrease the chances of resistance being selected. The use of lysostaphin in combination with a peptide may represent a new avenue in tackling drug-resistant staphylococci. PMID:21311938

  7. Iron requirement in the bactericidal mechanism of streptonigrin

    International Nuclear Information System (INIS)

    Mutants of Escherichia coli K-12 that are unable to make use of the enterochelin transport system were used to confirm that streptonigrin requires iron for its bactericidal action. Correlation of viability studies and 55Fe3+ uptake experiments showed that killing by streptonigrin increased with an increase in 55Fe3+ uptake by the cells. Fetreptonigrin did not kill iron-starved mutants that were unable to import iron. The level of iron uptake by these mutants was manipulated by agents such as the enterochelin biosynthetic precursors 2,3-dihydroxybenzoic acid (2 x 10(-5) M) and shikimic acid (2 x 10(-4) M), citrate (10(-2) M), which promotes iron uptake by an independent pathway, and the chelating agents desferrioxamine (2 x 10(-4) M) and orthophenanthroline (10(-4) M). Addition of the precursors shikimate and dihydroxybenzoate to strain AB2847 (aroB) and dihydroxybenzoate to strain AN193 (entA), allowing these strains to make enterochelin, resulted in an increase in Fe3+ uptake and a corresponding sharp increase in killing by streptonigrin. Addition of enterochelin itself (10(-6) M) caused an even more pronounced effect. Studies on the effect of citrate in strain AN102 (fep) showed that this mutant was not killed by streptonigrin (4 x 10(-5) M), even in the presence of citrate; however, overnight growth in citrate induced Fe3+ uptake by means of the ferric citrate transport system and resulted in killing by streptonigrin. These studies showed a clear correlation between the change in levels of intracellular iron and the bactericidal effectiveness of streptonigrin

  8. Bactericidal and cytotoxic effects of Erythrina fusca leaves aquadest extract

    Directory of Open Access Journals (Sweden)

    Janti Sudiono

    2013-03-01

    Full Text Available Background: Empirically, Erythrina fusca has been used as traditional herb for its antibacterial and antiinflammation properties. Periodontal disease is one of the most oral infectious diseases with microorganism predominated as the contributing factors. Porphyromonas gingivalis (P. gingivalis is one of the main bacteria pathogen found in periodontal diseases. Purpose: The purpose of this study was to examine the bactericidal effect of Erythrina fusca Leaves Aquadest Extract (EFLAE at various concentrations on P. gingivalis and cytotoxic effect on fibroblast. Methods: Pure P. gingivalis was cultured in Brain Heart Infusion (BHI medium for 24 hours with or without various concentrations of treatment of EFLAE. Calculation and statistical analysis of remaining bacteria were performed by inhibitory zone method to evaluate the EFLAE bactericidal effect and compared to chlorhexidine as positive control. To evaluate the cytotoxic effect, NIH 3T3 cells were cultured in Dulbecco’s Modification of Eagle’s Medium (DMEM containing of 10% fetal bovine serum (FBS and 1% penicillin-streptomycin, pH 7.2, in 5% CO2, and stored in humidified incubator under temperature 370 C. Cells were treated with/without various concentrations of EFLAE for 48 hours. The viable cells were then counted using 3-(4,5- Dimethylthiazol-2-yl-2,5 diphenyl tetrazodium bromide (MTT method. Results: EFLAE have bactericidal effect on P. gingivalis in a concentration dependent manner starting from 78%. The concentration of 90% EFLAE had stronger bactericidal effect (35.004 ± 1.546 than those of chlorhexidine as positive control (32.313 ± 1.619. One-way ANOVA showed significant bactericidal effect differences among concentrations of EFLAE and chlorhexidine (p<0.05 while Tuckey HSD test showed significant difference only between lower concentration of EFLAE (78%, 79% and chlorhexidine. With the highest concentration of EFLAE (100% applied in the bactericidal test, no cytotoxic effect

  9. The Application of Bactericidal Silver Nanoparticles in Wound Treatment

    Directory of Open Access Journals (Sweden)

    Geewoo Nam

    2015-07-01

    Full Text Available Even with the prevalence of wounds, the medical technol‐ ogy for efficiently managing skin damage is still primitive. The disruption of any of the numerous healing processes can lead to problems in the time-sensitive healing actions of the dermal and epidermal layers. Bacterial infection is one of the major obstacles to proper wound healing as it poses a danger of causing long-term negative effects. Keeping the wound free of bacteria is imperative to the proper and hasty repair of dermal wounds. Silver has been widely used to treat wounds for its bactericidal properties. Although the mechanism of silver’s antibacterial action is not fully understood, it exhibits a significant antimicrobial efficacy against a wide spectrum of bacterial species. A number of different approaches to the mechanism are reported and presented in this review. Silver nanoparticles (AgNPs have been reported to exhibit enhanced antibac‐ terial activity due to their increased surface-area-to-volume ratio. AgNPs are capable of various modifications, signifi‐ cantly broadening the therapeutic properties of the mate‐ rial as a result. This review explores the different aspects of silver and silver nanoparticles, and their antibacterial properties, which can be applied in the field of wound treatments.

  10. Preparation and bactericide activity of gallic acid stabilized gold nanoparticles

    International Nuclear Information System (INIS)

    In this work, gold nanoparticles with three different sizes (13.7, 39.4, and 76.7 nm) were prepared using a simple aqueous method with gallic acid as the reducing and stabilizing agent, the different sizes were obtained varying some experimental parameters as the pH of the reaction and the amount of the gallic acid. The prepared nanoparticles were characterized using X-ray diffraction, transmission electron microscopy, dynamic light scattering, and UV-Vis spectroscopy. Samples were identified as elemental gold and present spherical morphology, a narrow size distribution and good stabilization according to TEM and DLS results. The antibacterial activity of this gallic acid stabilized gold nanoparticles against S. mutans (the etiologic agent of dental caries) was assessed using a microdilution method obtaining a minimum inhibitory concentration of 12.31, 12.31, and 49.25 μg/mL for 13.7, 39.4, and 76.7 nm gold nanoparticles, respectively. The antibacterial assay showed that gold nanoparticles prepared in this work present a bactericide activity by a synergistic action with gallic acid. The MIC found for this nanoparticles are much lower than those reported for mixtures of gold nanoparticles and antibiotics.

  11. Preparation and bactericide activity of gallic acid stabilized gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Alvarez, S. A. [UASLP, Doctorado Institucional en Ingenieria y Ciencia de Materiales (Mexico); Martinez-Castanon, G. A., E-mail: mtzcastanon@fciencias.uaslp.m [UASLP, Maestria en Ciencias Odontologicas, Facultad de Estomatologia (Mexico); Nino-Martinez, N. [UASLP, Facultad de Ciencias (Mexico); Reyes-Macias, J. F.; Patino-Marin, N.; Loyola-Rodriguez, J. P. [UASLP, Maestria en Ciencias Odontologicas, Facultad de Estomatologia (Mexico); Ruiz, Facundo [UASLP, Facultad de Ciencias (Mexico)

    2010-10-15

    In this work, gold nanoparticles with three different sizes (13.7, 39.4, and 76.7 nm) were prepared using a simple aqueous method with gallic acid as the reducing and stabilizing agent, the different sizes were obtained varying some experimental parameters as the pH of the reaction and the amount of the gallic acid. The prepared nanoparticles were characterized using X-ray diffraction, transmission electron microscopy, dynamic light scattering, and UV-Vis spectroscopy. Samples were identified as elemental gold and present spherical morphology, a narrow size distribution and good stabilization according to TEM and DLS results. The antibacterial activity of this gallic acid stabilized gold nanoparticles against S. mutans (the etiologic agent of dental caries) was assessed using a microdilution method obtaining a minimum inhibitory concentration of 12.31, 12.31, and 49.25 {mu}g/mL for 13.7, 39.4, and 76.7 nm gold nanoparticles, respectively. The antibacterial assay showed that gold nanoparticles prepared in this work present a bactericide activity by a synergistic action with gallic acid. The MIC found for this nanoparticles are much lower than those reported for mixtures of gold nanoparticles and antibiotics.

  12. Bactericidal effect of Nd:YAG laser irradiation in endodontics

    Science.gov (United States)

    Aun, Carlos E.; Barberini, Alexandre F.; Camargo, Selma C. C.; Silva Kfouri, Luciana; Lorenzetti Simionato, Maria R.

    1999-05-01

    The success of endodontic therapy is based on the elimination of bacterial colonization from the endodontic system and periapical tissues. Recent studies have been showing the bactericidal effect of laser in root canal treatment. The propose of the study is to evaluate the effect of Nd:YAG laser irradiation in contaminated root canal treatment. The propose of the study is to evaluate the effect of Nd:YAG laser irradiation in contaminated root canals from upper central incisor. For the experiment 12 teeth were selected, respect at the apical third, sterilized, and 10 μm Streptococcus sanguis liquid culture were inoculated in the root canals. The laser test groups were irradiated with Nd:YAG laser at standard setting of 15Hz, 100mj and 1,5 W for 10, 20 and 30 seconds each in slow helicoidal movements from the apex to the top using a 300 micrometers fiber. After the procedure the specimens were placed in Tryptic Soy Agar, the number of colony forming units was evaluated. The experiment showed a significant reduction on viability of Streptococcus sanguis at the respective time of 20 and 30 seconds.

  13. Serum bactericidal activity as indicator of innate immunity in pacu Piaractus mesopotamicus (Holmberg, 1887

    Directory of Open Access Journals (Sweden)

    J.D. Biller-Takahashi

    2013-12-01

    Full Text Available The immune system of teleost fish has mechanisms responsible for the defense against bacteria through protective proteins in several tissues. The protein action can be evaluated by serum bactericidal activity and this is an important tool to analyze the immune system. Pacu, Piaractus mesopotamicus, is one of the most important fish in national aquaculture. However there is a lack of studies on its immune responses. In order to standardize and assess the accuracy of the serum bactericidal activity assay, fish were briefly challenged with Aeromonas hydrophila and sampled one week after the challenge. The bacterial infection increased the concentration of protective proteins, resulting in a decrease of colony-forming unit values expressed as well as an enhanced serum bactericidal activity. The protocol showed a reliable assay, appropriate to determine the serum bactericidal activity of pacu in the present experimental conditions.

  14. Increased bactericidal activity of colistin on Pseudomonas aeruginosa biofilms in anaerobic conditions

    OpenAIRE

    Kolpen, Mette; Appeldorff, Cecilie F.; Brandt, Sarah; Mousavi, Nabi; Kragh, Kasper N.; Aydogan, Sevtap; Uppal, Haleema A.; Bjarnsholt, Thomas; Ciofu, Oana; Høiby, Niels; Jensen, Peter Ø.

    2015-01-01

    Tolerance towards antibiotics of Pseudomonas aeruginosa biofilms is recognized as a major cause of therapeutic failure of chronic lung infection in cystic fibrosis (CF) patients. This lung infection is characterized by antibiotic-tolerant biofilms in mucus with zones of O2 depletion mainly due to polymorphonuclear leukocytic activity. In contrast to the main types of bactericidal antibiotics, it has not been possible to establish an association between the bactericidal effects of colistin and...

  15. Lactobacillus Proteins Are Associated with the Bactericidal Activity against E. coli of Female Genital Tract Secretions

    OpenAIRE

    Kalyoussef, Sabah; Nieves, Edward; Dinerman, Ellen; Carpenter, Colleen; Shankar, Viswanathan; Oh, Jamie; Burd, Berta; Angeletti, Ruth H.; Buckheit, Karen W.; Fredricks, David N.; Madan, Rebecca P.; Keller, Marla J.; Herold, Betsy C.

    2012-01-01

    Background Female genital tract secretions are bactericidal for Escherichia (E.) coli ex vivo. However, the intersubject variability and molecules that contribute to this activity have not been defined. Methods The bactericidal activity and concentration of immune mediators in cervicovaginal lavage (CVL) collected from 99 healthy women were determined. Results CVL reduced the number of E. coli colonies by 68% [−26, 100] (median [range]). CVL were active against laboratory and clinical isolate...

  16. Fungi and bacteria. [fungicide and bactericide measures for spacecraft in tropical regions

    Science.gov (United States)

    Daniels, G. E.

    1973-01-01

    Spacecraft equipment is usually protected from fungi and bacteria by incorporating a fungicide-bactericide in the material, by a fungicide-bactericide spray, or by reducing the relative humidity to a degree where growth will not take place. A unique method to protect delicate, expensive bearings in equipment was to maintain a pressure (with dry air or nitrogen) slightly above the outside atmosphere (few millibars) within the working parts of the equipment, thus preventing fungi from entering equipment.

  17. Effect of peritoneal dialysis fluid and pH on bactericidal activity of ciprofloxacin.

    OpenAIRE

    McCormick, E M; Echols, R M

    1987-01-01

    Ciprofloxacin is active in vitro against most bacteria that cause peritonitis associated with peritoneal dialysis. We compared the effects of pH (5.5 and 7.4) and medium (dialysis fluid) on the bactericidal activity of ciprofloxacin, tobramycin, vancomycin plus rifampin, and rifampin against Pseudomonas aeruginosa, Escherichia coli, and three strains of staphylococci. The bactericidal activity of ciprofloxacin was not significantly affected by pH or medium, in contrast to the activity of tobr...

  18. Cicada Wing Surface Topography: An Investigation into the Bactericidal Properties of Nanostructural Features.

    Science.gov (United States)

    Kelleher, S M; Habimana, O; Lawler, J; O' Reilly, B; Daniels, S; Casey, E; Cowley, A

    2016-06-22

    Recently, the surface of the wings of the Psaltoda claripennis cicada species has been shown to possess bactericidal properties and it has been suggested that the nanostructure present on the wings was responsible for the bacterial death. We have studied the surface-based nanostructure and bactericidal activity of the wings of three different cicadas (Megapomponia intermedia, Ayuthia spectabile and Cryptotympana aguila) in order to correlate the relationship between the observed surface topographical features and their bactericidal properties. Atomic force microscopy and scanning electron microscopy performed in this study revealed that the tested wing species contained a highly uniform, nanopillar structure on the surface. The bactericidal properties of the cicada wings were investigated by assessing the viability of autofluorescent Pseudomonas fluorescens cells following static adhesion assays and targeted dead/live fluorescence staining through direct microscopic counting methods. These experiments revealed a 20-25% bacterial surface coverage on all tested wing species; however, significant bactericidal properties were observed in the M. intermedia and C. aguila species as revealed by the high dead:live cell ratio on their surfaces. The combined results suggest a strong correlation between the bactericidal properties of the wings and the scale of the nanotopography present on the different wing surfaces. PMID:26551558

  19. Bactericidal action of positive and negative ions in air

    Directory of Open Access Journals (Sweden)

    Sleigh P Andrew

    2007-04-01

    . However in the case of Mycobacterium parafortuitum, electroporation resulting from exposure to the electric field appears to have been the principal cause of cell inactivation. Conclusion The results of the study suggest that the bactericidal action attributed to negative air ions by previous researchers may have been overestimated.

  20. The behavior of active bactericidal and antifungal coating under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Gang; Zhang, Xiaodong; Zhao, Yan; Su, Haijia, E-mail: suhj@mail.buct.edu.cn; Tan, Tianwei

    2014-02-15

    In the present paper, the novel active bactericidal and antifungal coatings (ABAC) have been prepared through the immobilization of Fe-doped TiO{sub 2} (anatase) with chitosan. The characterization of ABAC using optical microscope imaging, SEM, AFM and FTIR shows that the Fe doped TiO{sub 2} is embedded into the chitosan coating with favorable dispersion through the hydrogen bonds interaction between chitosan molecules and TiO{sub 2}. The contact angle measurement demonstrated the hydrophilicity of ABAC (θ = 34.5 ± 4.1°). The bactericidal activity of ABAC has been evaluated by inactivating three different test strains: Escherichia coli, Candida albicans and Aspergillus niger which illustrates the apparently higher bactericidal ability than chitosan, Fe-TiO{sub 2} and chitosan/TiO{sub 2} (pure) under visible light irradiation and its bactericidal activity is lasting for at least 24 h. ABAC showed rapid and efficient antibacterial ability for the three tested strains and its antibacterial ratio in 2 h for E. coli, C. albicans and A. niger was 99.9%, 97.0% and 95.0%, respectively. The prepared chitosan/TiO{sub 2} composite emulsion shows favorable storage stability and can be stored up to 1 year without losing its bactericidal activity. ABAC is a low-cost and eco-friendly antibacterial coating products and promising for domestic, medical and industrial applications.

  1. The behavior of active bactericidal and antifungal coating under visible light irradiation

    International Nuclear Information System (INIS)

    In the present paper, the novel active bactericidal and antifungal coatings (ABAC) have been prepared through the immobilization of Fe-doped TiO2 (anatase) with chitosan. The characterization of ABAC using optical microscope imaging, SEM, AFM and FTIR shows that the Fe doped TiO2 is embedded into the chitosan coating with favorable dispersion through the hydrogen bonds interaction between chitosan molecules and TiO2. The contact angle measurement demonstrated the hydrophilicity of ABAC (θ = 34.5 ± 4.1°). The bactericidal activity of ABAC has been evaluated by inactivating three different test strains: Escherichia coli, Candida albicans and Aspergillus niger which illustrates the apparently higher bactericidal ability than chitosan, Fe-TiO2 and chitosan/TiO2 (pure) under visible light irradiation and its bactericidal activity is lasting for at least 24 h. ABAC showed rapid and efficient antibacterial ability for the three tested strains and its antibacterial ratio in 2 h for E. coli, C. albicans and A. niger was 99.9%, 97.0% and 95.0%, respectively. The prepared chitosan/TiO2 composite emulsion shows favorable storage stability and can be stored up to 1 year without losing its bactericidal activity. ABAC is a low-cost and eco-friendly antibacterial coating products and promising for domestic, medical and industrial applications.

  2. Bactericidal and anti-adhesive properties of culinary and medicinal plants against Helicobacter pylori

    Institute of Scientific and Technical Information of China (English)

    Rachel O'Mahony; Huda Al-Khtheeri; Deepeka Weerasekera; Neluka Fernando; Dino Vaira; John Holton; Christelle Basset

    2005-01-01

    AIM: To investigate the bactericidal and anti-adhesive properties of 25 plants against Helicobacter pylori (H pylori).METHODS: Twenty-five plants were boiled in water to produce aqueous extracts that simulate the effect of cooking. The bactericidal activity of the extracts was assessed by a standard kill-curve with seven strains of H pylori. The anti-adhesive property was assessed by the inhibition of binding of four strains of FITC-labeled H pylori to stomach sections. RESULTS: Of all the plants tested, eight plants, including Bengal quince, nightshade, garlic, dill, black pepper, coriander, fenugreek and black tea, were found to have no bactericidal effect on any of the isolates. Columbo weed, long pepper, parsley, tarragon, nutmeg, yellow-berried nightshade, threadstem carpetweed, sage and cinnamon had bactericidal activities against H pylori, but total inhibition of growth was not achieved in this study. Among the plants that killed H pylori, turmeric was the most efficient, followed by cumin, ginger, chilli, borage, black caraway, oregano and liquorice. Moreover, extracts of turmeric; borage and parsley were able to inhibit the adhesion of H pylori strains to the stomach sections.CONCLUSION: Several plants that were tested in our study had bactericidal and/or anti-adhesive effects on H pylori. Ingestion of the plants with anti-adhesive properties could therefore provide a potent alternative therapy for H pylori infection, which overcomes the problem of resistance associated with current antibiotic treatment.

  3. [Comparative urinary bactericidal activity of oral antibiotics against gram-positive pathogens].

    Science.gov (United States)

    Bedenić, Branka; Budimir, Ana; Gverić, Ana; Plecko, Vanda; Vranes, Jasmina; Bubonja-Sonje, Marina; Kalenić, Smilja

    2012-01-01

    In routine bacteriological laboratories the antibacterial activity of antibiotics is determined by in vitro testing, usually by disk-diffusion test. However, in vitro testing does not always reflect antibacterial efficiency of antibiotics in vivo. In this investigation, the urine samples obtained in a single oral dose pharmacokinetic study were examined for their bactericidal activity against a range of relevant Gram-positive urinary tract pathogens. Urinary bactericidal activity of linezolid had been previously compared with ciprofloxacin but not with other oral antibiotics such as beta-lactams. Linezolid showed satisfactory urinary bactericidal titres throughout the whole testing period against all Gram-positive cocci. Fluoroquinolones displayed high and persisting levels of urinary bactericidal activity against staphylococci, but their activity against enterococci was weaker. According to the results of ex-vivo testing amoxycillin could be recommended only for infections caused by E. faecalis. Amoxycillin combined with clavulanic acid can be considered as a therapeutic option for infections caused by S. saprophyticus and E. faecalis. Older cephalosporins had high titres only against S. saprophyticus. Their drawback is a short elimination half-time in urine resulting in rapid decrease of urinary bactericidal titers during dosing interval. Furthermore, they do not show activity against enterococci due to their intrinsic resistance to cephalosporins. PMID:22930932

  4. The bactericidal effect of surface micro-discharge plasma under different ambient conditions

    Science.gov (United States)

    Shimizu, T.; Zimmermann, J. L.; Morfill, G. E.

    2011-02-01

    A series of experiments on the bactericidal properties of plasmas using a surface micro-discharge (SMD) device in an atmosphere under different ambient temperatures and humidities was carried out. This plasma dispenser was developed for use as a disinfection system in private and public places (hospitals, medical practices, etc). The bactericidal effect is due to the interplay of the plasma and the chemical products produced via interactions with O2/N2 and H2O vapour in air. To use this device in different countries and therefore under various ambient conditions, it is important to understand its behaviour and efficiency, especially with respect to air temperature and humidity. The experimental results obtained in this study show that the bactericidal properties of the SMD plasma dispenser are not sensitive to the different temperatures and humidities.

  5. Increased bactericidal activity of colistin on Pseudomonas aeruginosa biofilms in anaerobic conditions

    DEFF Research Database (Denmark)

    Mette, Kolpen; Appeldorff, Cecilie F; Brandt, Sarah;

    2016-01-01

    polymorphonuclear leukocytic activity. In contrast to the main types of bactericidal antibiotics, it has not been possible to establish an association between the bactericidal effects of colistin and the production of detectable levels of OH⋅ on several strains of planktonic P. aeruginosa. Therefore we propose that...... production of OH⋅ may not contribute significantly to the bactericidal activity of colistin on P. aeruginosa biofilm. Thus, we investigated the effect of colistin treatment on biofilm of wildtype PAO1, a catalase deficient mutant (ΔkatA) and a colistin resistant CF isolate cultured in microtiter plates in...... normoxic- or anoxic atmosphere with 1 mM nitrate. The killing of bacteria during colistin treatment was measured by CFU counts and the OH⋅ formation was measured by 3'-(p-hydroxylphenyl fluorescein) fluorescein (HPF) fluorescence. Validation of the assay was done by hydrogenperoxide treatment. OH...

  6. Effects of cytochalasin B on the intrcellular bactericidal activity of human neutrophils.

    Science.gov (United States)

    Okuda, K

    1975-06-01

    Cytochalasin B (CB) is known to have some inhibitory effects on cytokinesis, single-cell movement, bacterial uptake by phagocytes, and many other processes. The effects of CB on intraleukocytic bactericidal activities in human leukocytes were studied, and the results were summarized as follows. (i) CB inhibited the early stage of the intracellular bactericidal activity of human leukocytes against Streptococcus pyogenes D58 (group A). The effect was rapidly eliminated by rinsing the CB solution. (ii) In the late stage of the intracellular bactericidal process, however, CB possessed no effect against S. pyogenes D58 (group A) and Staphylococcus aureus 209P. (iii) CB also inhibited the translocation of myeloperoxidase granules to the phagosomes of human neutrophils. PMID:1155917

  7. Morphology-dependent bactericidal activities of Ag/CeO2 catalysts against Escherichia coli.

    Science.gov (United States)

    Wang, Lian; He, Hong; Yu, Yunbo; Sun, Li; Liu, Sijin; Zhang, Changbin; He, Lian

    2014-06-01

    Silver-loaded CeO2 nanomaterials (Ag/CeO2) including Ag/CeO2 nanorods, nanocubes, nanoparticles were prepared with hydrothermal and impregnation methods. Catalytic inactivation of Escherichia coli with Ag/CeO2 catalysts through the formation of reactive oxygen species (ROS) was investigated. For comparison purposes, the bactericidal activities of CeO2 nanorods, nanocubes and nanoparticles were also studied. There was a 3-4 log order improvement in the inactivation of E. coli with Ag/CeO2 catalysts compared with CeO2 catalysts. Temperature-programmed reduction of H2 showed that Ag/CeO2 catalysts had higher catalytic oxidation ability than CeO2 catalysts, which was the reason for that Ag/CeO2 catalysts exhibited stronger bactericidal activities than CeO2 catalysts. Further, the bactericidal activities of CeO2 and Ag/CeO2 depend on their shapes. Results of 5,5-dimethyl-1-pyrroline-N-oxide spin-trapping measurements by electron spin resonance and addition of catalase as a scavenger indicated the formation of OH, O2(-), and H2O2, which caused the obvious bactericidal activity of catalysts. The stronger chemical bond between Ag and CeO2 nanorods led to lower Ag(+) elution concentrations. The toxicity of Ag(+) eluted from the catalysts did not play an important role during the bactericidal process. Experimental results also indicated that Ag/CeO2 induced the production of intracellular ROS and disruption of the cell wall and cell membrane. A possible production mechanism of ROS and bactericidal mechanism of catalytic oxidation were proposed. PMID:24662462

  8. Susceptibility of Helicobacter pylori to bactericidal properties of medium-chain monoglycerides and free fatty acids.

    Science.gov (United States)

    Petschow, B W; Batema, R P; Ford, L L

    1996-01-01

    Previous studies have shown that various short- and medium-chain free fatty acids (FFAs) and their corresponding monoacylglycerol esters (MGs) have antibacterial activity in vitro against primarily gram-positive bacteria. More recent studies have also shown that the growth of Helicobacter spp. is inhibited by linoleic acid and arachidonic acid. The purpose of the present study was to evaluate the susceptibility of Helicobacter pylori to the in vitro bactericidal properties of medium-chain MGs and FFAs. Incubation of H. pylori with saturated MGs, ranging in carbon chain length from C10:0 to C14:0, at 1 mM caused a 4-log-unit or greater reduction in the number of viable bacteria after exposure for 1 h. Lower levels of bactericidal activity were observed with C9:0, C15:0, and C16:0 MGs. In contrast, lauric acid (C12:0) was the only medium-chain saturated FFA with bactericidal activity against H. pylori. The MGs and FFAs were bactericidal after incubation for as little as 15 min at neutral or acidic pHs. Higher levels of MGs and FFAs were required for bactericidal activity in the presence of higher amounts of protein in liquid diets. We also found that the frequency of spontaneous development of resistance by H. pylori was higher for metronidazole and tetracycline (10(-5) to 10(-6)) than for C10:0 MG, C12:0 MG, and C12:0 FFA (< 10(-8)). Collectively, our data demonstrate that H. pylori is rapidly inactivated by medium-chain MGs and lauric acid and exhibits a relatively low frequency of spontaneous development of resistance to the bactericidal activity of MGs. Further studies are needed to establish whether MGs may be useful either alone or with other known therapeutic agents in the management of H. pylori infections in humans. PMID:8834870

  9. A new method for measuring simultaneously the phagocytic and bactericidal capacity of human leukocytes

    International Nuclear Information System (INIS)

    A new technique for simultaneously measuring the phagocytic and bactericidal capacity of human leukocytes is proposed. The method uses 14C labelled bacteria and is based on the principle that only viable intra-cellular bacteria incorporate 3H-thymidine. Phagocytosis is measured by the ratio intra-cellular 14C/extra and intra-cellular 14C and the bactericidal capacity of leukocytes by the difference between the 3H-thymidine incorporation of the ingested and non-ingested bacteria. Results in normal subjects and in a case of chronic granulomatous disease show the validity of the method which is easier and quicker than the methods previously used

  10. Whole-blood phagocytic and bactericidal activities of atomic bomb survivors, Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    This in vitro study evaluated the phagocytic and bactericidal activities of leukocytes in aliquots of whole blood from Hiroshima and Nagasaki atomic bomb survivors for Staphylococcus aureus. The data were analyzed by multiple linear regression. Any significant effects of exposure to A-bomb radiation could not be detected for both phagocytic and bactericidal activities of whole blood from A-bomb survivors. In addition, there were no significant effects of age categories, sex or city, except in neutrophil counts. (J.P.N.)

  11. Bactericide Effect of Atmospheric Plasma of Flat and Comb Electrodes on Escherichia coli

    OpenAIRE

    A. Hosseinzadeh Colagar; F. Sohbatzadeh; S. Mirzanejhad; N. Asadian

    2008-01-01

    Objective: The current study was undertaken to examine the bactericide effects of atmospheric plasma produced by flat and comb electrodes on E.coli.Materials and Methods: DC (20 W) and AC (500 W) power supplies, flat and comb electrodes, insulator and oxygen gas were used to produce atmospheric plasma. Bactericide effects of the atmospheric plasma were studied on E.coli on sterilized plate placed on ice powder, at 3 McFarland concentration.Results: Flow of the atmospheric plasma produced by f...

  12. The nature of inherent bactericidal activity: insights from the nanotopology of three species of dragonfly

    Science.gov (United States)

    Mainwaring, David E.; Nguyen, Song Ha; Webb, Hayden; Jakubov, Timur; Tobin, Mark; Lamb, Robert N.; Wu, Alex H.-F.; Marchant, Richard; Crawford, Russell J.; Ivanova, Elena P.

    2016-03-01

    While insect wings are widely recognised as multi-functional, recent work showed that this extends to extensive bactericidal activity brought about by cell deformation and lysis on the wing nanotopology. We now quantitatively show that subtle changes to this topography result in substantial changes in bactericidal activity that are able to span an order of magnitude. Notably, the chemical composition of the lipid nanopillars was seen by XPS and synchrotron FTIR microspectroscopy to be similar across these activity differences. Modelling the interaction between bacterial cells and the wing surface lipids of 3 species of dragonflies, that inhabit similar environments, but with distinctly different behavioural repertoires, provided the relationship between surface structure and antibacterial functionality. In doing so, these principal behavioural patterns correlated with the demands for antimicrobial efficiency dictated by differences in their foraging strategies. This work now reveals a new feature in the design elegance of natural multi-functional surfaces as well providing insights into the bactericidal mechanism underlying inherently antimicrobial materials, while suggesting that nanotopology is related to the evolutionary development of a species through the demands of its behavioural repertoire. The underlying relationship between the processes of wetting, adhesion and capillarity of the lipid nanopillars and bactericidal efficiency suggests new prospects for purely mechano-responsive antibacterial surfaces.While insect wings are widely recognised as multi-functional, recent work showed that this extends to extensive bactericidal activity brought about by cell deformation and lysis on the wing nanotopology. We now quantitatively show that subtle changes to this topography result in substantial changes in bactericidal activity that are able to span an order of magnitude. Notably, the chemical composition of the lipid nanopillars was seen by XPS and synchrotron

  13. The bactericidal activity of β-lactam antibiotics is increased by metabolizable sugar species

    DEFF Research Database (Denmark)

    Thorsing, Mette; Bentin, Thomas; Givskov, Michael;

    2015-01-01

    establishing sugar metabolism as an important factor influencing the bactericidal outcome of β-lactam treatment. Interestingly, the effect of sugar on β-lactam susceptibility was suppressed in a strain unable to synthesize the nutrient stress alarmone (p)ppGpp. Here, to the best of our knowledge, we...

  14. Hierarchical Polymer Brushes with Dominant Antibacterial Mechanisms Switching from Bactericidal to Bacteria Repellent.

    Science.gov (United States)

    Yan, Shunjie; Luan, Shifang; Shi, Hengchong; Xu, Xiaodong; Zhang, Jidong; Yuan, Shuaishuai; Yang, Yuming; Yin, Jinghua

    2016-05-01

    Although polycationic surfaces have high antimicrobial efficacies, they suffer from high toxicity to mammalian cells and severe surface accumulation of dead bacteria. For the first time, we propose a surface-initiated photoiniferter-mediated polymerization (SI-PIMP) strategy of constructing a "cleaning" zwitterionic outer layer on a polycationic bactericidal background layer to physically hinder the availability of polycationic moieties for mammalian cells in aqueous service. In dry conditions, the polycationic layer exerts the contact-active bactericidal property toward the adherent bacteria, as the zwitterionic layer collapses. In aqueous environment, the zwitterionic layer forms a hydration layer to significantly inhibit the attachment of planktonic bacteria and the accumulation of dead bacteria, while the polycationic layer kills bacteria occasionally deposited on the surface, thus preserving the antibacterial capability for a long period. More importantly, the zwitterionic hydrated layer protects the mammalian cells from toxicity induced by the bactericidal background layer, and therefore hierarchical antibacterial surfaces present much better biocompatibility than that of the naked cationic references. The dominant antibacterial mechanism of the hierarchical surfaces can switch from the bactericidal efficacy in dry storage to the bacteria repellent capability in aqueous service, showing great advantages in the infection-resistant applications. PMID:27049327

  15. Lactobacillus proteins are associated with the bactericidal activity against E. coli of female genital tract secretions.

    Directory of Open Access Journals (Sweden)

    Sabah Kalyoussef

    Full Text Available BACKGROUND: Female genital tract secretions are bactericidal for Escherichia (E. coli ex vivo. However, the intersubject variability and molecules that contribute to this activity have not been defined. METHODS: The bactericidal activity and concentration of immune mediators in cervicovaginal lavage (CVL collected from 99 healthy women were determined. RESULTS: CVL reduced the number of E. coli colonies by 68% [-26, 100] (median [range]. CVL were active against laboratory and clinical isolates of E. coli, but were inactive against Lactobacillus species. Bactericidal activity correlated with the concentration of protein recovered (p90% inhibitory activity (active and two with<30% activity were subjected to MS/MS proteomic analysis. 215 proteins were identified and six were found exclusively in active samples. Four of these corresponded to Lactobacillus crispatus or jensenii proteins. Moreover, culture supernatants from Lactobacillus jensenii were bactericidal for E. coli. CONCLUSION: Both host and commensal microbiota proteins contribute to mucosal defense. Identification of these proteins will facilitate the development of strategies to maintain a healthy vaginal microbiome and prevent colonization with pathogenic bacteria such as E. coli that increase the risk for urinary tract infections, preterm labor and perinatal infection.

  16. [Bacteriostatic effect and/or xylitol bactericide of crops on Listeria Monocytogenes].

    Science.gov (United States)

    Morón de Salim, Alba Rosa; Ramírez Mérida, Luis Guillermo

    2013-06-01

    Listeria monocytogenes has been considered as an emerging pathogen causing foodborne illness. In the search for an alternate route biocontrol propagation, xylitol has been proposed as a possible bacteriostatic and / or bactericide. Xylitol is a polyol derived from the hydrogenation of xylose monosaccharide of importance in the pharmaceutical industry for its anti-cariogenic effect. To check the possible effect of xylitol as bacteriostatic and/or bactericidal against Listeria monocytogenes, it was determined the minimum inhibitory concentration (MIC), the time minimum inhibition (TMI) and minimum bactericidal concentration (MBC) of xylitol solutions on Listeria monocytogenes ATCC 7635. The agar diffusion method was applied, using xylitol solutions at concentrations of 0-10%, respectively, for the MIC. The TMI was determined by growth curves in trypticase soy broth with solutions 1, 2, 3, 5, 8, 9, 10 and 20% of xylitol, respectively, with an initial inoculum of 108 CFU per ml of Listeria monocytogenes in each solution. MIC observed was the solution 1% of xylitol; the TMI was 10 hours to concentrations of 1 to 10% and 7 hours to apply 20% xylitol. It was found that xylitol has bacteriostatic power on Listeria monocytogenes (p < 0.001), but not bactericide effect. PMID:24934074

  17. Bactericidal Activity of Quinupristin-Dalfopristin against Staphylococcus aureus: Clindamycin Susceptibility as a Surrogate Indicator

    OpenAIRE

    Fuchs, Peter C.; Barry, Arthur L.; Brown, Steven D.

    2000-01-01

    Of 516 Staphylococcus aureus strains tested, 97.1% were susceptible to quinupristin-dalfopristin, which was bactericidal for 22 (56%) of the 39 strains tested, comparable to vancomycin. All 17 clindamycin and macrolide-resistant strains were inhibited but not killed by quinupristin-dalfopristin, whereas all 22 clindamycin-susceptible strains (5 were macrolide resistant) were killed.

  18. 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

  19. Delayed bactericidal response of Mycobacterium tuberculosis to bedaquiline involves remodelling of bacterial metabolism

    DEFF Research Database (Denmark)

    Koul, A.; Vranckx, L.; Dhar, N.;

    2014-01-01

    Bedaquiline (BDQ), an ATP synthase inhibitor, is the first drug to be approved for treatment of multidrug-resistant tuberculosis in decades. Though BDQ has shown excellent efficacy in clinical trials, its early bactericidal activity during the first week of chemotherapy is minimal. Here, using...

  20. Green Synthesis of Silver Nanoparticles and Their Bactericidal and Antimycotic Activities against Oral Microbes

    OpenAIRE

    Rodríguez-Luis, Osvelia E.; Hernandez-Delgadillo, Rene; Sánchez-Nájera, Rosa Isela; Martínez-Castañón, Gabriel Alejandro; Niño-Martínez, Nereyda; Sánchez Navarro, María del Carmen; Ruiz, Facundo; Cabral-Romero, Claudio

    2016-01-01

    Nanotechnology is a new discipline with huge applications including medicine and pharmacology industries. Although several methods and reducing agents have been employed to synthesize silver nanoparticles, reactive chemicals promote toxicity and nondesired effects on the human and biological systems. The objective of this work was to synthesize silver nanoparticles from Glycyrrhiza glabra and Amphipterygium adstringens extracts and determine their bactericidal and antimycotic activities again...

  1. LED array designing and its bactericidal effect researching on Pseudomonas aeruginosa in vitro

    Science.gov (United States)

    Fang, Jing; Xing, Jin; Gao, Liucun; Shen, Benjian; Kang, Hongxiang; Jie, Liang; Peng, Chen

    2015-10-01

    Lights with some special waveband and output power density have a bactericidal effect to some special bacteria. In this paper, the bactericidal effect of light at wavelength of 470 nm on P. aeruginosa (ATCC 27853) is researched with different irradiation dose. The light source is a LED array which is obtained by incoherent combine of 36 LEDs with emitting wavelength of 470 nm. The P. aeruginosa suspension is exposed with the LED array at the light power density of 100 mW/cm2 with exposures time of 0, 5, 10, 20, 40, and 80 min, respectively. The numbers of CFU are then determined by serial dilutions on LB agar plates. The bactericidal effect research results of 470 nm LED on P. aeruginosa show that the killing ratio increases with increasing of the exposure time. For the 80 min irradiation, as much as 92.4% reduction of P. aeruginosa is achieved. The results indicate that, in vitro, 470-nm lights produce dose dependent bactericidal effects on P. aeruginosa.

  2. Following the Mechanisms of Bacteriostatic versus Bactericidal Action Using Raman Spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Bernatová, Silvie; Samek, Ota; Pilát, Zdeněk; Šerý, Mojmír; Ježek, Jan; Jákl, Petr; Šiler, Martin; Krzyžánek, Vladislav; Zemánek, Pavel; Holá, V.; Dvořáčková, M.; Růžička, F.

    2013-01-01

    Roč. 18, č. 11 (2013), s. 13188-13199. ISSN 1420-3049 R&D Projects: GA MŠk ED0017/01/01; GA ČR GAP205/11/1687 Institutional support: RVO:68081731 Keywords : Raman spectroscopy * antibiotics * bacteria * bactericidal * bacteriostatic Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 2.095, year: 2013

  3. Characterization and Activity of an Immobilized Antimicrobial Peptide Containing Bactericidal PEG-Hydrogel

    NARCIS (Netherlands)

    Cleophas, Rik T. C.; Sjollema, Jelmer; Busscher, Henk J.; Kruijtzer, John A. W.; Liskamp, Rob M. J.

    2014-01-01

    A single step immobilization-polymerization strategy of a highly active antimicrobial peptide into a soft hydrogel network on a poly(ethylene terephthalate) surface using thiol-ene chemistry is described. The bactericidal hydrogel was molecularly characterized via Coomassie and Lowry assay protein s

  4. A complex of equine lysozyme and oleic acid with bactericidal activity against Streptococcus pneumoniae.

    Directory of Open Access Journals (Sweden)

    Emily A Clementi

    Full Text Available HAMLET and ELOA are complexes consisting of oleic acid and two homologous, yet functionally different, proteins with cytotoxic activities against mammalian cells, with HAMLET showing higher tumor cells specificity, possibly due to the difference in propensity for oleic acid binding, as HAMLET binds 5-8 oleic acid molecules per protein molecule and ELOA binds 11-48 oleic acids. HAMLET has been shown to possess bactericidal activity against a number of bacterial species, particularly those with a respiratory tropism, with Streptococcus pneumoniae displaying the greatest degree of sensitivity. We show here that ELOA also displays bactericidal activity against pneumococci, which at lower concentrations shows mechanistic similarities to HAMLET's bactericidal activity. ELOA binds to S. pneumoniae and causes perturbations of the plasma membrane, including depolarization and subsequent rupture, and activates an influx of calcium into the cells. Selective inhibition of calcium channels and sodium/calcium exchange activity significantly diminished ELOA's bactericidal activity, similar to what we have observed with HAMLET. Finally, ELOA-induced death was also accompanied by DNA fragmentation into high molecular weight fragments - an apoptosis-like morphological phenotype that is seen during HAMLET-induced death. Thus, in contrast to different mechanisms of eukaryote cell death induced by ELOA and HAMLET, these complexes are characterized by rather similar activities towards bacteria. Although the majority of these events could be mimicked using oleic acid alone, the concentrations of oleic acid required were significantly higher than those present in the ELOA complex, and for some assays, the results were not identical between oleic acid alone and the ELOA complex. This indicates that the lipid, as a common denominator in both complexes, is an important component for the complexes' bactericidal activities, while the proteins are required both to solubilize

  5. Nanoparticle synthesis of zinc peroxide: structural and morphological characterization for bactericidal applications

    International Nuclear Information System (INIS)

    Zinc peroxide (ZnO2) nanoparticles were synthesized by sol-gel technique. The chemicals used for the synthesis were zinc acetate di-hydrate (Zn(CH3COO)2.2H2O) and hydrogen peroxide (H2O2) at 30 % in an aqueous solution with sonication. The structure of the ZnO2 nanoparticles was characterized by X-ray diffraction. While the morphology and the cluster size were determined using scanning and transmission electron microscopy. For a preliminary evaluation of the bactericidal properties of the ZnO2, the material was exposed to Staphylococcus aureus, Escherichia coli y Bacillus subtili, and the nanoparticles presented good bactericidal properties. (author)

  6. Reinforcement of the bactericidal effect of ciprofloxacin on Pseudomonas aeruginosa biofilm by hyperbaric oxygen treatment

    DEFF Research Database (Denmark)

    Kolpen, Mette; Mousavi, Nabi; Sams, Thomas;

    2016-01-01

    diffusive supply for aerobic respiration during ciprofloxacin treatment. This proof-of-principle study demonstrates that biofilm reoxygenation by HBOT can significantly enhance the bactericidal activity of ciprofloxacin on P. aeruginosa. Combining ciprofloxacin treatment with HBOT thus clearly has potential...... mechanisms affecting antibiotic effectiveness on biofilms remain unclear, accumulating evidence suggests that the efficacy of several bactericidal antibiotics such as ciprofloxacin is enhanced by stimulation of the aerobic respiration of pathogens, and that lack of O2 increases their tolerance. Reoxygenation...... of O2-depleted biofilms may thus improve susceptibility to ciprofloxacin possibly by restoring aerobic respiration. We tested such a strategy using reoxygenation of O2-depleted P. aeruginosa strain PAO1 agarose-embedded biofilms by hyperbaric oxygen treatment (HBOT) (100% O2, 2.8bar), enhancing the...

  7. Bactericidal Antibiotics Do Not Appear To Cause Oxidative Stress in Listeria monocytogenes

    DEFF Research Database (Denmark)

    Feld, Louise; Knudsen, Gitte Maegaard; Gram, Lone

    2012-01-01

    to cause oxidative stress in L. monocytogenes and propose that this is caused by its noncyclic tricarboxylic acid (TCA) pathway. Hence, in this noncyclic metabolism, there is a decoupling between the antibiotic-mediated cellular requirement for NADH and the induction of TCA enzyme activity, which......Oxidative stress can be an important contributor to the lethal effect of bactericidal antibiotics in some bacteria, such as Escherichia coli and Staphylococcus aureus. Thus, despite the different target-specific actions of bactericidal antibiotics, they have a common mechanism leading to bacterial...... self-destruction by internal production of hydroxyl radicals. The purpose of the present study was to determine if a similar mechanism is involved in antibiotic killing of the infectious human pathogen, Listeria monocytogenes. We treated wild-type L. monocytogenes and oxidative stress mutants (Δsod...

  8. In-vitro bactericidal activity of maggots of the green blowfly (Lucilia sericata)

    OpenAIRE

    Daeschlein, Georg; Hoffmeister, Britta; Below, Harald; Kramer, Axel

    2006-01-01

    Maggots of Lucilia sericata are used as an alternative to surgical intervention and long-term antiseptic therapy for the treatment of chronic wounds. To quantify the bactericidal effect of secretions from larvae, an in-vitro test model based on the modified European quantitative suspension test (EN 1040) was developed, in which a co-culture of maggots and bacteria (Micrococcus luteus, Escherichia coli, Methicillin-sensitive Staphylococcus aureus) in tryptic soy broth was tested. The numbers o...

  9. Bactericidal efficacy of elevated pH on fish pathogenic and environmental bacteria

    Science.gov (United States)

    Starliper, Clifford E.; Watten, Barnaby J.

    2013-01-01

    Ship ballast water is a recognized medium for transfer and introductions of nonindigenous species. There is a need for new ballast water treatment methods that effectively and safely eliminate or greatly minimize movements of these species. The present study employed laboratory methods to evaluate the bactericidal efficacy of increased pH (pH 10.0–12.0) for exposure durations of up to 72 h to kill a variety of Gram-negative and Gram-positive bacteria including fish pathogens (Aeromonas spp., Yersinia ruckeri, Edwardsiella ictaluri, Serratia liquefaciens, Carnobacterium sp.), other common aquatic-inhabitant bacteria (Serratia marcescens, Pseudomonas fluorescens, Staphylococcus sp., Bacillus sp.) and indicators listed in International Maritime Organization D2 Standards; namely, Vibrio cholera (an environmental isolate from fish), Escherichia coli and Enterococcus faecalis. Volumes of 5 N NaOH were added to tryptic soy broth to obtain desired pH adjustments. Viable cells were determined after 0, 4, 12, 24, 48, and 72 h. Initial (0 h) cell numbers ranged from 3.40 × 104 cfu/mL for Bacillus sp. to 2.44 × 107 cfu/mL for E. faecalis. The effective endpoints of pH and treatment duration necessary to realize 100% bactericidal effect varied; however, all bacteria tested were killed within 72 h at pH 12.0 or lower. The lowest parameters examined, 4 h at pH 10.0, were bactericidal to V. cholera, E. ictaluri, three of four isolates of E. coli, and (three of four) Aeromonas salmonicida subsp. salmonicida. Bactericidal effect was attained at pH 10.0 within 12 h for the other A. salmonicida subsp. salmonicida, and within 24 h for P. fluorescens, and the remaining E. coli.

  10. Bactericidal Effect of Aqueous Extracts of the Bark of the Pomegranate (Punica granatum L.) on Bacteria

    OpenAIRE

    Rabah Chadli; Aman Bouzid; Khadidja Bouzid; Hamida Nader

    2015-01-01

    This research concerns the study of antibacterial properties of different aqueous extracts of the bark of the pomegranate (Punica granatum L.). Three bacterial strains were used in this test: Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella. Very interesting bactericidal properties of aqueous extracts of the bark of the pomegranate were found on bacteria. The inhibition zones have a very large diameter up to 20 mm and the MIC and MBC are low, of the order of 0.78 mg/ml. This work ...

  11. Early Bactericidal Activity of Moxifloxacin in Treatment of Pulmonary Tuberculosis: a Prospective, Randomized Study

    OpenAIRE

    Pletz, Mathias W. R.; De Roux, Andres; Roth, Andreas; NEUMANN, Karl-Heinz; Mauch, Harald; Lode, Hartmut

    2004-01-01

    Moxifloxacin is the most active fluoroquinolone against Mycobacterium tuberculosis in vitro. However, data about the efficacy in patients are not available. We enrolled 17 patients with tuberculosis in a prospective, randomized study. After 5 days of monotherapy with either moxifloxacin or isoniazid, we detected significant decreases in mean CFU per milliliter in sputum in both groups. The calculated early bactericidal activities for isoniazid and moxifloxacin were 0.209 and 0.273 log10 CFU p...

  12. Bactericidal Activity of Multiple Combinations of Tigecycline and Colistin against NDM-1-Producing Enterobacteriaceae

    OpenAIRE

    Albur, Mahableshwar; Noel, Alan; Bowker, Karen; MacGowan, Alasdair

    2012-01-01

    The interaction between colistin and tigecycline against eight well-characterized NDM-1-producing Enterobacteriaceae strains was studied. Time-kill methodology was employed using a 4-by-4 exposure matrix with pharmacokinetically achievable free drug peak, trough, and average 24-h serum concentrations. Colistin sulfate and methanesulfonate alone showed good early bactericidal activity, often with subsequent regrowth. Tigecycline alone had poor activity. Addition of tigecycline to colistin does...

  13. Bactericidal Activity of Some Lichen Secondary Compounds of Cladonia ochrochlora , Parmotrema nilgherrensis & Parmotrema sancti-angelii

    Directory of Open Access Journals (Sweden)

    VERMA NEERAJ

    2011-06-01

    Full Text Available In the present study, bactericidal potential of some lichen secondary compounds has been presented. Three lichen species namely Cladonia ochrochlora, Parmotrema nilgherrensis and Parmotrema sancti-angelii were successively fractionated in various organic solvents nhexane, ethyl acetate, acetone and methanol. The ethyl acetate fraction (10 μg/ml of these lichen species showed promised bactericidal activity and the order of the activity of lichen species were found as P. nilgherrensis > P. sanctiangelii > C. ochrochlora. Seven lichen secondary compounds alectoronic acid, atranorin, $-collatolic acid, fumarprotocetraric acid, hypoprotocetraric acid, lecanoric acid and protocetraric acid isolated from ethyl acetate fraction of above lichen species demonstrated moderate to strong bactericidal activity with low MIC value; alectoronic acid showed MIC 21.9 μg to 162.1 μg/ml, atranorin (5 μg - 70.7 μg/ml, $-collatolic acid (8.6 μg - 245 μg/ml, fumarprotocetraric acid (24 μg - 227.3 μg/ml, hypoprotocetraric acid (12.2 μg - 278.5 μg/ml, lecanoric acid (24.6 μg - 591.7 μg/ml, protocetraric acid (18.7 μg - 740.7 μg/ml. These secondary compounds were found most effective to kill microorganisms within a period of 0 hrs to 6 hrs incubation as evident from the kinetic time kill assay study. As far as the stability of the lichen compounds for the observed activity, it was found that these compounds were stable at 4oC without loosing their bactericidal potential.

  14. Investigation of the bactericidal effects of vancomycin and quinupristin/dalfopristin on Staphylococcus aureus isolates

    OpenAIRE

    HOŞGÖR-LİMONCU, Mine; ERMERTCAN, Şafak; COŞAR, Güner

    2004-01-01

    The present study aimed to determine the correlation between the bactericidal activity of vancomycin and quinupristin/dalfopristin (Q/D) on Staphylococcus aureus isolates and their minimal inhibition concentrations. The in-vitro susceptibilities of the 99 S. aureus isolates to vancomycin and Q/D were investigated by agar dilution. Thirty methicillin-resistant S. aureus (MRSA) and 30 methicillin-susceptible S. aureus (MSSA) vancomycin and Q/D susceptible isolates were involved in time-kill stu...

  15. Untersuchungen zur Expression und Regulation von murinem Bactericidal/ Permeability Increasing Protein (BPI)

    OpenAIRE

    Eckert, Melanie

    2007-01-01

    LPS-bindende Proteine repräsentieren eine wichtige Säule bei der Bekämpfung von gramnegativen Bakterien durch das angeborene Immunsystem. Zum einen liefern sie einen wichtigen Beitrag bei der hochsensitiven Erkennung gramnegativer Bakterien, zum anderen können sie durch die Neutralisation von LPS die Ausbildung eines septischen Schocks durch eine überschießende Immunantwort verhindern. Humanes Bactericidal/ Permeability Increasing Protein (BPI) ist als LPS-bindendes Protein beschrieben. Es ze...

  16. Electrochemical analysis of the UV treated bactericidal Ti6Al4V surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Pacha-Olivenza, Miguel A. [Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) (Spain); Department of Applied Physics, Faculty of Science, University of Extremadura, Av. Elvas s/n, 06071 Badajoz (Spain); Gallardo-Moreno, Amparo M., E-mail: amparogm@unex.es [Department of Applied Physics, Faculty of Science, University of Extremadura, Av. Elvas s/n, 06071 Badajoz (Spain); Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) (Spain); Vadillo-Rodríguez, Virginia; González-Martín, M. Luisa [Department of Applied Physics, Faculty of Science, University of Extremadura, Av. Elvas s/n, 06071 Badajoz (Spain); Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) (Spain); Pérez-Giraldo, Ciro [Department of Microbiology, Faculty of Medicine, University of Extremadura, Av. Elvas s/n, 06071 Badajoz (Spain); Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) (Spain); Galván, Juan C. [National Centre for Metallurgical Research (CENIM-CSIC), Av. Gregorio del Amo 8, 28040-Madrid (Spain)

    2013-04-01

    This research investigates in detail the bactericidal effect exhibited by the surface of the biomaterial Ti6Al4V after being subjected to UV-C light. It has been recently hypothesized that small surface currents, occurring as a consequence of the electron–hole pair recombination taking place after the excitation process, are behind the bactericidal properties displayed by this UV-treated material. To corroborate this hypothesis we have used different electrochemical techniques, such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization plots and Mott–Schottky plots. EIS and Mott–Schottky plots have shown that UV-C treatment causes an initial increase on the surface electrical conduction of this material. In addition, EIS and polarization plots demonstrated that higher corrosion currents occur at the UV treated than at the non-irradiated samples. Despite this increase in the corrosion currents, EIS has also shown that such currents are not likely to affect the good stability of this material oxide film since the irradiated samples completely recovered the control values after being stored in dark conditions for a period not longer than 24 h. These results agree with the already-published in vitro transitory behavior of the bactericidal effect, which was shown to be present at initial times after the biomaterial implantation, a crucial moment to avoid a large number of biomaterial associated infections. Highlights: ► Bactericidal response of UV-treated Ti6Al4V is explained through electrochemistry. ► There is an increase in the superficial electrical conduction after UV-treatment. ► Higher corrosion currents for UV-treated against non-UV-treated samples are shown. ► EIS shows the recuperation on irradiated samples in agreement with microbial tests.

  17. Bactericidal effect of 5-azacytidine on Escherichia coli carrying EcoRII restriction-modification enzymes.

    OpenAIRE

    Friedman, S.

    1982-01-01

    5-Azacytidine was found to be bactericidal to Escherichia coli carrying plasmids specifying EcoRII restriction-modification systems, but not to the same strains lacking these plasmids. Of other base analogs tested, only 5(beta-D-ribofuranosyl)isocytidine had similar, although weaker, effects. Plasmids that had lost the EcoRII restriction-modification system did not confer sensitivity to 5-azacytidine. Mutants defective in the restriction function remained sensitive to the toxic effects of the...

  18. Verapamil Increases the Bactericidal Activity of Bedaquiline against Mycobacterium tuberculosis in a Mouse Model

    OpenAIRE

    Gupta, Shashank; Tyagi, Sandeep; Bishai, William R.

    2014-01-01

    Bedaquiline is a newly approved drug for the treatment of multidrug-resistant tuberculosis, but there are concerns about its safety in humans. We found that the coadministration of verapamil with subinhibitory doses of bedaquiline gave the same bactericidal effect in mice as did the full human bioequivalent bedaquiline dosing. Adding verapamil to bedaquiline monotherapy also protected against the development of resistant mutants in vivo. The adjunctive use of verapamil may permit use of lower...

  19. Delayed bactericidal response of Mycobacterium tuberculosis to bedaquiline involves remodelling of bacterial metabolism

    OpenAIRE

    Koul, Anil; Vranckx, Luc; Dhar, Neeraj; Gohlmann, Hinrich W. H.; Özdemir, Muhittin Emre; Neefs, Jean-Marc; Schulz, Melanie; Lu, Ping; Mortz, Ejvind; McKinney, John D.; Andries, Koen; Bald, Dirk

    2014-01-01

    Bedaquiline (BDQ), an ATP synthase inhibitor, is the first drug to be approved for treatment of multidrug-resistant tuberculosis in decades. Though BDQ has shown excellent efficacy in clinical trials, its early bactericidal activity during the first week of chemotherapy is minimal. Here, using microfluidic devices and time-lapse microscopy of Mycobacterium tuberculosis, we confirm the absence of significant bacteriolytic activity during the first 3-4 days of exposure to BDQ. BDQ-induced inhib...

  20. Bactericidal efficacy of elevated pH on fish pathogenic and environmental bacteria

    Directory of Open Access Journals (Sweden)

    Clifford E. Starliper

    2013-07-01

    Full Text Available Ship ballast water is a recognized medium for transfer and introductions of nonindigenous species. There is a need for new ballast water treatment methods that effectively and safely eliminate or greatly minimize movements of these species. The present study employed laboratory methods to evaluate the bactericidal efficacy of increased pH (pH 10.0–12.0 for exposure durations of up to 72 h to kill a variety of Gram-negative and Gram-positive bacteria including fish pathogens (Aeromonas spp., Yersinia ruckeri, Edwardsiella ictaluri, Serratia liquefaciens, Carnobacterium sp., other common aquatic-inhabitant bacteria (Serratia marcescens, Pseudomonas fluorescens, Staphylococcus sp., Bacillus sp. and indicators listed in International Maritime Organization D2 Standards; namely, Vibrio cholera (an environmental isolate from fish, Escherichia coli and Enterococcus faecalis. Volumes of 5 N NaOH were added to tryptic soy broth to obtain desired pH adjustments. Viable cells were determined after 0, 4, 12, 24, 48, and 72 h. Initial (0 h cell numbers ranged from 3.40 × 104 cfu/mL for Bacillus sp. to 2.44 × 107 cfu/mL for E. faecalis. The effective endpoints of pH and treatment duration necessary to realize 100% bactericidal effect varied; however, all bacteria tested were killed within 72 h at pH 12.0 or lower. The lowest parameters examined, 4 h at pH 10.0, were bactericidal to V. cholera, E. ictaluri, three of four isolates of E. coli, and (three of four Aeromonas salmonicida subsp. salmonicida. Bactericidal effect was attained at pH 10.0 within 12 h for the other A. salmonicida subsp. salmonicida, and within 24 h for P. fluorescens, and the remaining E. coli.

  1. Differential complement activation and susceptibility to human serum bactericidal action by Vibrio species.

    OpenAIRE

    1983-01-01

    The ability of Vibrio vulnificus to resist human serum bactericidal action and to activate human complement was compared with similar cultures of Vibrio cholerae and Vibrio parahaemolyticus. Both V. vulnificus and V. parahaemolyticus had similar survival rates in sera and were much more resistant to killing than was V. cholerae. In contrast, V. vulnificus activated significantly less serum complement than did V. cholerae and V. parahaemolyticus. The relative ability of V. vulnificus to surviv...

  2. Platelets release mitochondria serving as substrate for bactericidal group IIA-secreted phospholipase A2 to promote inflammation

    OpenAIRE

    Boudreau, Luc H.; Duchez, Anne-Claire; Cloutier, Nathalie; Soulet, Denis; Martin, Nicolas; Bollinger, James; Paré, Alexandre; Rousseau, Matthieu; Naika, Gajendra S.; Lévesque, Tania; Laflamme, Cynthia; Marcoux, Geneviève; Lambeau, Gérard; Farndale, Richard W.; Pouliot, Marc

    2014-01-01

    When activated and in platelet storage bags, platelets release respiratory-competent mitochondria, a recognized damage-associated molecular pattern.Mitochondria, descendant of Rickettsia prowazekii, serve as substrate for bactericidal sPLA2-IIA to promote inflammation.

  3. [Bacteriostatic and/or bactericidal extract of Aloe vera gel on cultures of Listeria monocytogenes].

    Science.gov (United States)

    Ramírez Mérida, Luis Guillermo; Morón de Salim, Alba; Catinella, Rosangela; Castillo, Luis

    2012-03-01

    Listeria monocytogenes is a bacteria responsible for food borne diseases (FBD). The effect of Aloe vera gel extract as a possible bacteriostatic and/or bactericidal against Listeria monocytogenes, was checked by determined the minimum inhibitory concentration (MIC), the time of minimum inhibition (TMI) and minimum bactericidal concentration (MBC) solutions extract of Aloe vera gel in different concentrations on cultures of Listeria monocytogenes ATCC 7635. We applied the agar diffusion method, using solutions of extract of Aloe vera gel at concentrations of 0 to 100% for the MIC. The TMI was determined by growth curves in trypticase soy broth with an initial inoculum of Listeria monocytogenes ATCC 7635 of 108 CFU/mL in each solution. It was determined that the MIC was 10% extract of Aloe vera gel and TMI was 5 hours at concentrations of 10%, 20% and 30% of Aloe vera, while concentrations of 50, 80, 90 and 100%, the time was 8 hours. It was found that indeed the Aloe vera gel is bacteriostatic power on Listeria monocytogenes (p < 0.001), but yet, no bactericidal effect was obtained in our study. PMID:23477211

  4. In vitro bactericidal activities of Japanese rice-fluid against Helicobacter pylori strains

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Kawakami, Kozue Oana, Masayoshi Hayama, Hiroyoshi Ota, Masahiko Takeuchi, Kazuhiro Miyashita, Tsunetomo Matsuzawa, Kiyomi Kanaya

    2006-01-01

    Full Text Available Background: Helicobacter pylori has now been widely recognized as a causative agent of gastroduodenal diseases. The development of safer anti- H. pylori compounds is desirable due to the antibiotic-resistant strains emerged to date. Methods: We successfully developed the compounds of Rice-fluid derived from unpolished, polished, and usually cooked Japanese rice, and investigated their in vitro antibacterial activities by means of the Time-Kill-Curve methods against various species of bacteria including H. pylori strains. Results: All of the compounds revealed keen bactericidal activities against H. pylori, followed by Streptococcus pneumoniae and Campylobacter jejuni strains, but failed to affect the viability of other bacterial species investigated including staphylococci, enterococci, Pseudomonas aeruginosa, and other gram-negative rods belonging to the family Enterobacteraceae. The bactericidal activities were demonstrated to be time- and concentration-dependent. Conclusions: The compounds of Rice-fluid are considered to be potentially new and safe therapeutic regimens against H. pylori infections. The mechanism of their bactericidal activities against H. pylori strains remains to be elucidated.

  5. Bactericidal activity of Musca domestica cecropin (Mdc) on multidrug-resistant clinical isolate of Escherichia coli.

    Science.gov (United States)

    Lu, X; Shen, J; Jin, X; Ma, Y; Huang, Y; Mei, H; Chu, F; Zhu, J

    2012-08-01

    The housefly (Musca domestica) larvae have been used clinically to cure osteomyelitis, decubital necrosis, lip boil, ecthyma and malnutritional stagnation ever since the Ming/Qing Dynasty (1368 Anno Domini) till now, in China. In prior research, we have cloned and characterized a new gene of antimicrobial peptide cecropin from M. domestica larvae. This peptide was potently active against Gram-positive and Gram-negative bacteria standard strain. In the present study, we evaluated the possibility of Mdc to be a potential bactericidal agent against clinical isolates of multidrug-resistant (MDR) Escherichia coli and to elucidate the related antimicrobial mechanisms. Antimicrobial activity assays indicated a minimal inhibitory concentration (MIC) of 1.56 μM. Bactericidal kinetics at MIC showed that Mdc rapid killing of MDR E. coli. Lipopolysaccharide (LPS) dose-dependently suppressed Mdc antibacterial potency indicates that LPS is the initial binding site of Mdc in E. coli. Propidium iodide-based flow cytometry revealed that Mdc causes E. coli membrane permeabilization. Transmission electron micrographs further indicated that a remarkable damage in the bacteria's outer and inner membrane, even the leakage of cytoplasmic contents induced by Mdc. DNA binding experimental result implies that DNA is one of the possible intracellular targets of Mdc. Of note, Mdc did not show a perceptible cytotoxic effect on human red blood cells. Altogether, these results suggest that Mdc could be an excellent candidate for the development of more efficacious bactericidal agents. PMID:22202966

  6. Bactericidal effect of a 405-nm diode laser on Porphyromonas gingivalis

    International Nuclear Information System (INIS)

    The study was conducted to determine the effect of 405-nm diode laser irradiation on periodontopathic bacteria such as Porphyromonas gingivalis in vitro. A diluted suspension of P. gingivalis was irradiated directly with a 405-nm diode laser under conditions of 100 mW-10 sec, 100 mW-20 sec, 200 mW-5 sec, 200 mW-10 sec, 200 mW-20 sec, 400 mW-5 sec, 400 mW-10 sec, and 400 mW-20 sec. The energy density ranged from 2.0 to 16.0 J/cm2. The irradiated bacterial suspension was spread on a blood agar plate and growth of the colonies was examined after an anaerobic culture for 7 days. Bacterial growth was inhibited under all irradiation conditions, but the bactericidal effect of the 405-nm diode laser depended on the energy density. More than 97% of bacterial growth was inhibited with irradiation at an energy density > 4.0 J/cm2. The mechanism of the bactericidal effect is photochemical, rather than photothermal. These findings suggest that a 405-nm diode laser has a high bactericidal effect on P. gingivalis

  7. Direct Comparison of Xpert MTB/RIF Assay with Liquid and Solid Mycobacterial Culture for Quantification of Early Bactericidal Activity

    OpenAIRE

    Kayigire, Xavier A.; Friedrich, Sven O.; Venter, Amour; Dawson, Rodney; Gillespie, Stephen Henry; Boeree, Martin J.; Heinrich, Norbert; Hoelscher, Michael; Diacon, Andreas H.

    2013-01-01

    The early bactericidal activity of antituberculosis agents is usually determined by measuring the reduction of the sputum mycobacterial load over time on solid agar medium or in liquid culture. This study investigated the value of a quantitative PCR assay for early bactericidal activity determination. Groups of 15 patients were treated with 6 different antituberculosis agents or regimens. Patients collected sputum for 16 h overnight at baseline and at days 7 and 14 after treatment initiation....

  8. Mechanisms of α-defensin bactericidal action: COMPARATIVE MEMBRANE DISRUPTION BY CRYPTDIN-4 AND ITS DISULFIDE-NULL ANALOG†

    OpenAIRE

    Hadjicharalambous, Chrystalleni; Sheynis, Tanya; Jelinek, Raz; Shanahan, Michael T.; Ouellette, Andre J.; Gizeli, Electra

    2008-01-01

    Mammalian α-defensins all have a conserved triple-stranded β-sheet structure that is constrained by an invariant tridisulfide array, and the peptides exert bactericidal effects by permeabilizing the target cell envelope. Curiously, the disordered, disulfide-null variant of mouse α-defensin cryptdin-4 (Crp4), termed (6C/A)-Crp4, has equal or greater bactericidal activity than the native peptide, providing rationale for comparing the mechanisms by which the peptides interact with and disrupt ph...

  9. Analysis by confocal laser scanning microscopy of the MDPB bactericidal effect on S. mutans biofilm CLSM analysis of MDPB bactericidal effect on biofilm

    Directory of Open Access Journals (Sweden)

    Fabíola Galbiatti de Carvalho

    2012-10-01

    Full Text Available Since bacteria remain in the dentin following caries removal, restorative materials with antibacterial properties are desirable to help maintaining the residual microorganisms inactive. The adhesive system Clearfil Protect Bond (PB contains the antibacterial monomer 12-methacryloyloxydodecylpyridinium bromide (MDPB in its primer, which has shown antimicrobial activity. However, its bactericidal effect against biofilm on the dentin has been little investigated. Objective: The aim of this study was to analyze by confocal laser scanning microscopy (CLSM and viable bacteria counting (CFU the MDPB bactericidal effect against S. mutans biofilm on the dentin surface. Material and methods: Bovine dentin surfaces were obtained and subjected to S. mutans biofilm formation in BHI broth supplemented with 1% (w/v sucrose for 18 h. Samples were divided into three groups, according to the primer application (n=3: Clearfil Protect Bond (PB, Clearfil SE Bond, which does not contain MDPB, (SE and saline (control group. After the biofilm formation, Live/ Dead stain was applied directly to the surface of each sample. Next, 10 µL of each primer were applied on the samples during 590 s for the real-time CLSM analysis. The experiment was conducted in triplicate. The primers and saline were also applied on the other dentin samples during 20, 90, 300 and 590 s (n=9 for each group and period evaluated and the CFU were assessed by colonies counting. Results: The results of the CLSM showed that with the Se application, although non-viable bacteria were detected at 20 s, there was no increase in their count during 590 s. In contrast, after the PB application there was a gradual increase of non-viable bacteria over 590 s. Conclusions: The quantitative analysis demonstrated a significant decrease of S. mutans CFU at 90 s PB exposure and only after 300 s of Se application. Protect Bond showed an earlier antibacterial effect than Se Bond.

  10. Systemic hypoxia enhances exercise-mediated bactericidal and subsequent apoptotic responses in human neutrophils.

    Science.gov (United States)

    Wang, Jong-Shyan; Chiu, Ya-Ting

    2009-10-01

    Phagocytosis and oxidative burst are critical host defense mechanisms in which neutrophils clear invading pathogens. Clearing phagocytic neutrophils by triggering apoptosis is an essential process for controlling inflammation. This study elucidates how various exercise bouts with/without hypoxia affected neutrophil bactericidal activity and subsequent apoptosis in humans. Fifteen sedentary males performed six distinct experimental tests in an air-conditioned normobaric hypoxia chamber: two normoxic exercises [strenuous exercise (SE; up to maximal O2 consumption) and moderate exercise (ME; 50% maximal O2 consumption for 30 min) while exposed to 21% O2], two hypoxic exercises (ME for 30 min while exposed to 12% and 15% O2), and two hypoxic exposures (resting for 30 min while exposed to 12% and 15% O2). The results showed that 1) plasma complement-C3a desArg/C4a desArg/C5a concentrations were increased, 2) expressions of L-selectin/lymphocyte functin-associated antigen-1/Mac-1/C5aR on neutrophils were enhanced, 3) phagocytosis of neutrophils to Esherichia coli and release of neutrophil oxidant products by E. coli were elevated, and 4) E. coli-induced phosphotidylserine exposure or caspase-3 activation of neutrophils were promoted immediately and 2 h after both 12% O2 exposure at rest and with ME as well as normoxic SE. Although neither normoxic ME nor breathing 15% O2 at rest influenced these complement- and neutrophil-related immune responses, ME at both 12% and 15% O2 resulted in enhanced complement activation in the blood, expressions of opsonic/complement receptors on neutrophils, or the bactericidal activity and apoptosis of neutrophils. Moreover, the increased neutrophil oxidant production and apoptosis by normoxic SE and hypoxic ME were ameliorated by treating neutrophils with diphenylene iodonium (a NADPH oxidase inhibitor). Therefore, we conclude that ME at 12-15% O2 enhances bactericidal capacity and facilitates the subsequent apoptosis of neutrophils. PMID

  11. Association of Bactericidal Dysfunction of Paneth Cells in Streptozocin-Induced Diabetic Mice with Insulin Deficiency.

    Science.gov (United States)

    Yu, Tao; Yang, Hong-Sheng; Lu, Xi-Ji; Xia, Zhong-Sheng; Ouyang, Hui; Shan, Ti-Dong; Huang, Can-Ze; Chen, Qi-Kui

    2016-01-01

    BACKGROUND Type 1 diabetes mellitus (T1DM) is associated with increased risks of enteric infection. Paneth cells constitute the first line of the gut defense. Little is known about the impact of T1DM on the bactericidal function of intestinal Paneth cells. MATERIAL AND METHODS A T1DM mouse model was induced by intraperitoneal injection of streptozocin. The analysis of intestinal microbiota and the mucosal bactericidal assay were conducted to evaluate intestinal innate defense. Numbers of Paneth cells and their expression of related antimicrobial peptides were analyzed. Expression of total insulin receptor (IR) mRNA and relative levels of IR-A/IR-B were analyzed. The primary mouse small intestinal crypt culture was used to analyze the effect of insulin and glucose on the expression of related antimicrobial peptides of Paneth cells. RESULTS In T1DM mice, bacterial loads were increased and there was an alteration in the composition of the intestinal microflora. Exogenous bacteria had better survival in the small bowel of the T1DM mice. The expression of Paneth cell-derived antimicrobial peptides was significantly decreased in the T1DM mice, although the number of Paneth cells was increased. Relative levels of IR-A/IR-B in Paneth cells of diabetic mice were elevated, but the total IR mRNA did not change. Insulin treatment restored the expression of antimicrobial peptides and normalized the microbiota in the gut of T1DM mice. Subsequently, in vitro culture assay demonstrated that insulin rather than glucose was essential for the optimal expression of Paneth cell-derived antimicrobial peptides. CONCLUSIONS The bactericidal function of intestinal Paneth cells was impaired in STZ-induced diabetic mice, resulting in the altered intestinal flora, and insulin was essential for the optimal expression of Paneth cell-derived antimicrobial peptides. PMID:27572949

  12. Comprehensive bactericidal activity of an ethanol-based hand gel in 15 seconds

    OpenAIRE

    Kampf Günter; Hollingsworth Angela

    2008-01-01

    Abstract Background Some studies indicate that the commonly recommended 30 s application time for the post contamination treatment of hands may not be necessary as the same effect may be achieved with some formulations in a shorter application time such as 15 s. Method We evaluated the bactericidal activity of an ethanol-based hand gel (Sterillium® Comfort Gel) within 15 s in a time-kill-test against 11 Gram-positive, 16 Gram-negative bacteria and 11 emerging bacterial pathogens. Each strain ...

  13. Bactericidal effect of colistin on planktonic Pseudomonas aeruginosa is independent of hydroxyl radical formation

    DEFF Research Database (Denmark)

    Brochmann, Rikke Prejh; Toft, Anders; Ciofu, Oana;

    2014-01-01

    The bactericidal effect of several major types of antibiotics has recently been demonstrated to be dependent on the formation of toxic amounts of hydroxyl radicals (OH·) resulting from oxidative stress in metabolically active cells. Since killing by the antimicrobial peptide colistin does not...... require bacterial metabolic activity, we tested whether the bactericidal effect of colistin depends on the formation of OH·. In Pseudomonas aeruginosa cultures, OH-mediated killing by ciprofloxacin was demonstrated by decreased bacterial survival and induction of 3'-(p-hydroxyphenyl) fluorescein (HPF......· was seen in P. aeruginosa during killing by colistin, and prevention of OH· accumulation could not rescue P. aeruginosa from killing by colistin. These results therefore demonstrate that the bactericidal activity of colistin on P. aeruginosa is not dependent on oxidative stress. In conclusion...

  14. An investigation of the bactericidal activity of selected essential oils to Aeromonas spp.

    Directory of Open Access Journals (Sweden)

    Clifford E. Starliper

    2015-01-01

    Full Text Available Diseases of fishes caused by Aeromonas spp. are common, have broad host ranges and may cause high mortality. Treatments of captive-reared populations using antimicrobials are limited with concerns for bacterial resistance development and environmental dissemination. This study was done to determine whether selected plant-derived essential oils were bactericidal to Aeromonas spp. Initially, twelve essential oils were evaluated using a disk diffusion assay to an isolate of A. salmonicida subsp. salmonicida, cause of fish furunculosis. The greatest zones of inhibition were obtained with oils of cinnamon Cinnamomum cassia, oregano Origanum vulgare, lemongrass Cymbopogon citratus and thyme Thymus vulgaris. Minimum bactericidal concentrations (MBC’s were determined for these four oils, Allimed® (garlic extract, Allium sativum and colloidal silver to sixty-nine isolates representing nine Aeromonas spp. The lowest mean MBCs (0.02–0.04% were obtained with three different sources of cinnamon oil. MBCs for three sources of oregano and lemongrass oils ranged from 0.14% to 0.30% and 0.10% to 0.65%, respectively, and for two thyme oils were 2.11% and 2.22%. The highest concentration (5% of Allimed® tested resulted in MBCs to twelve isolates. A concentration of silver greater than 15 mg/L would be required to determine MBCs for all but one isolate.

  15. Bactericidal Antibiotics Induce Toxic Metabolic Perturbations that Lead to Cellular Damage

    Directory of Open Access Journals (Sweden)

    Peter Belenky

    2015-11-01

    Full Text Available Understanding how antibiotics impact bacterial metabolism may provide insight into their mechanisms of action and could lead to enhanced therapeutic methodologies. Here, we profiled the metabolome of Escherichia coli after treatment with three different classes of bactericidal antibiotics (β-lactams, aminoglycosides, quinolones. These treatments induced a similar set of metabolic changes after 30 min that then diverged into more distinct profiles at later time points. The most striking changes corresponded to elevated concentrations of central carbon metabolites, active breakdown of the nucleotide pool, reduced lipid levels, and evidence of an elevated redox state. We examined potential end-target consequences of these metabolic perturbations and found that antibiotic-treated cells exhibited cytotoxic changes indicative of oxidative stress, including higher levels of protein carbonylation, malondialdehyde adducts, nucleotide oxidation, and double-strand DNA breaks. This work shows that bactericidal antibiotics induce a complex set of metabolic changes that are correlated with the buildup of toxic metabolic by-products.

  16. Encapsulation of titanium dioxide nanoparticles in PLA microspheres using supercritical emulsion extraction to produce bactericidal nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Campardelli, R., E-mail: rcampardelli@unisa.it; Della Porta, G. [University of Salerno, Department of Industrial Engineering (Italy); Gomez, V.; Irusta, S. [University of Zaragoza, Aragon Institute of Nanoscience (INA) (Spain); Reverchon, E., E-mail: ereverchon@unisa.it [University of Salerno, Department of Industrial Engineering (Italy); Santamaria, J., E-mail: jesus.santamaria@unizar.es [University of Zaragoza, Aragon Institute of Nanoscience (INA) (Spain)

    2013-10-15

    In this work, PLA microparticles containing TiO{sub 2} (anatase) nanoparticles have been produced using the Continuous Supercritical Emulsion Extraction technique (SEE-C). A stabilized anatase colloidal suspension (15 {+-} 5 nm) in ethanol aqueous solution was obtained by precipitation from solutions of titanium alkoxides and directly used as the water internal phase of a water-in-oil in water double emulsion or suspended as a powder in the organic phase of a solid-in-oil in water emulsion. Micro- (0.9 {+-} 0.5 {mu}m) and submicro-particles (203 {+-} 40 nm) have been produced, with TiO{sub 2} nominal loadings of 1.2, 2.4, and 3.6 wt%. High TiO{sub 2} encapsulation efficiencies up to about 90 % have been obtained. PLA/TiO{sub 2} particles have been characterized by TEM and XPS to investigate the dispersion of the metal oxide in the polymeric matrix. The photo-assisted bactericidal activity of TiO{sub 2}-containing microparticles against a biofilm-forming strain of Staphylococcus aureus was investigated in specific assays under UV light. Pure TiO{sub 2} nanoparticles and PLA/TiO{sub 2} particles showed the same bactericidal activity.

  17. Green Synthesis of Silver Nanoparticles and Their Bactericidal and Antimycotic Activities against Oral Microbes

    Directory of Open Access Journals (Sweden)

    Osvelia E. Rodríguez-Luis

    2016-01-01

    Full Text Available Nanotechnology is a new discipline with huge applications including medicine and pharmacology industries. Although several methods and reducing agents have been employed to synthesize silver nanoparticles, reactive chemicals promote toxicity and nondesired effects on the human and biological systems. The objective of this work was to synthesize silver nanoparticles from Glycyrrhiza glabra and Amphipterygium adstringens extracts and determine their bactericidal and antimycotic activities against Enterococcus faecalis and Candida albicans growth, respectively. 1 and 10 mM silver nitrate were mixed with an extract of Glycyrrhiza glabra and Amphipterygium adstringens. Green silver nanoparticles (AgNPs were characterized by TEM, Vis-NIR, FTIR, fluorescence, DLS, TGA, and X-ray diffraction (XRD analysis. Bactericidal and antimycotic activities of AgNPs were determined by Kirby and Bauer method and cell viability MTT assays. AgNPs showed a spherical shape and average size of 9 nm if prepared with Glycyrrhiza glabra extract and 3 nm if prepared with Amphipterygium adstringens extract. AgNPs inhibited the bacterial and fungal growth as was expected, without a significant cytotoxic effect on human epithelial cells. Altogether, these results strongly suggest that AgNPs could be an interesting option to control oral biofilms.

  18. An investigation of the bactericidal activity of selected essential oils to Aeromonas spp.

    Science.gov (United States)

    Starliper, Clifford E; Ketola, Henry G; Noyes, Andrew D; Schill, William B; Henson, Fred G; Chalupnicki, Marc A; Dittman, Dawn E

    2015-01-01

    Diseases of fishes caused by Aeromonas spp. are common, have broad host ranges and may cause high mortality. Treatments of captive-reared populations using antimicrobials are limited with concerns for bacterial resistance development and environmental dissemination. This study was done to determine whether selected plant-derived essential oils were bactericidal to Aeromonas spp. Initially, twelve essential oils were evaluated using a disk diffusion assay to an isolate of A. salmonicida subsp. salmonicida, cause of fish furunculosis. The greatest zones of inhibition were obtained with oils of cinnamon Cinnamomum cassia, oregano Origanum vulgare, lemongrass Cymbopogon citratus and thyme Thymus vulgaris. Minimum bactericidal concentrations (MBC's) were determined for these four oils, Allimed® (garlic extract, Allium sativum) and colloidal silver to sixty-nine isolates representing nine Aeromonas spp. The lowest mean MBCs (0.02-0.04%) were obtained with three different sources of cinnamon oil. MBCs for three sources of oregano and lemongrass oils ranged from 0.14% to 0.30% and 0.10% to 0.65%, respectively, and for two thyme oils were 2.11% and 2.22%. The highest concentration (5%) of Allimed® tested resulted in MBCs to twelve isolates. A concentration of silver greater than 15 mg/L would be required to determine MBCs for all but one isolate. PMID:25685547

  19. Antibacterial properties and mechanism of graphene oxide-silver nanocomposites as bactericidal agents for water disinfection.

    Science.gov (United States)

    Song, Biao; Zhang, Chang; Zeng, Guangming; Gong, Jilai; Chang, Yingna; Jiang, Yan

    2016-08-15

    Providing clean and affordable drinking water without harmful disinfection byproducts generated by conventional chemical disinfectants gives rise to the need for technological innovation. Nanotechnology has great potential in purifying water and wastewater treatment. A graphene oxide-silver (GO-Ag) nanocomposite with excellent antibacterial activity was prepared and characterized by transmission electron microscope and X-ray photoelectron spectroscopy. The tests were carried out using Escherichia coli and Staphylococcus aureus as model strains of Gram-negative and Gram-positive bacteria, respectively. The effect of bactericide dosage and pH on antibacterial activity of GO-Ag was examined. Morphological observation of bacterial cells by scanning electron microscope showed that GO-Ag was much more destructive to cell membrane of Escherichia coli than that of Staphylococcus aureus. Experiments were carried out using catalase, superoxide dismutase and sodium thioglycollate to investigate the formation of reactive oxygen species and free silver ions in the bactericidal process. The activity of intracellular antioxidant enzymes was measured to investigate the potential role of oxidative stress. According to the consequence, synergetic mechanism including destruction of cell membranes and oxidative stress accounted for the antibacterial activity of GO-Ag nanocomposites. All the results suggested that GO-Ag nanocomposites displayed a good potential for application in water disinfection. PMID:27170600

  20. Characterization of Mechanical and Bactericidal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanomaterials

    Directory of Open Access Journals (Sweden)

    Pawel Sikora

    2016-08-01

    Full Text Available The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a new use was found for it: instead of creating waste, it can be recycled as an additive in building materials. The aim of the study was to evaluate the possibility of manufacturing sustainable and self-cleaning cement mortars with use of commercially available nanomaterials and brown soda-lime waste glass. Mechanical and bactericidal properties of cement mortars containing brown soda-lime waste glass and commercially available nanomaterials (amorphous nanosilica and cement containing nanocrystalline titanium dioxide were analyzed in terms of waste glass content and the effectiveness of nanomaterials. Quartz sand is replaced with brown waste glass at ratios of 25%, 50%, 75% and 100% by weight. Study has shown that waste glass can act as a successful replacement for sand (up to 100% to produce cement mortars while nanosilica is incorporated. Additionally, a positive effect of waste glass aggregate for bactericidal properties of cement mortars was observed.

  1. Encapsulation of titanium dioxide nanoparticles in PLA microspheres using supercritical emulsion extraction to produce bactericidal nanocomposites

    International Nuclear Information System (INIS)

    In this work, PLA microparticles containing TiO2 (anatase) nanoparticles have been produced using the Continuous Supercritical Emulsion Extraction technique (SEE-C). A stabilized anatase colloidal suspension (15 ± 5 nm) in ethanol aqueous solution was obtained by precipitation from solutions of titanium alkoxides and directly used as the water internal phase of a water-in-oil in water double emulsion or suspended as a powder in the organic phase of a solid-in-oil in water emulsion. Micro- (0.9 ± 0.5 μm) and submicro-particles (203 ± 40 nm) have been produced, with TiO2 nominal loadings of 1.2, 2.4, and 3.6 wt%. High TiO2 encapsulation efficiencies up to about 90 % have been obtained. PLA/TiO2 particles have been characterized by TEM and XPS to investigate the dispersion of the metal oxide in the polymeric matrix. The photo-assisted bactericidal activity of TiO2-containing microparticles against a biofilm-forming strain of Staphylococcus aureus was investigated in specific assays under UV light. Pure TiO2 nanoparticles and PLA/TiO2 particles showed the same bactericidal activity

  2. Environmental monitoring and bactericidal efficacy of chlorine dioxide gas in a dental office.

    Science.gov (United States)

    Kuroyama, Iwao; Osato, Shigeo; Nakajima, Shigeki; Kubota, Ryoichi; Ogawa, Takahiro

    2010-09-01

    We monitored the quantity of airborne microorganisms at 11 points (points A to K) in a dental office on a routine day of use, and tested the bactericidal efficacy of chlorine dioxide (ClO₂) gas in the dental operatory after consulting hours. Fallen airborne microorganisms were collected under air-conditioning (AC) in the dental office, and under four conditions in the operatory. Specimens of the microbes were cultivated on nutrient and Sabouraud agar media (NAM and SAM). Many colonies were observed at the entrance hall and on the cabinet in a disinfection room in the NAM and SAM tests, respectively, while no colony was observed at the foot position of the operating table and treatment bed, and above the head position of the operating room in the NAM and SAM tests, respectively. In the bactericidal efficacy test using ClO₂ gas, the dental operatory could be kept clean by the use of 4 mg/L-ClO₂ gas in addition to the use of an AC with a plasma filter and the HEPA filter. PMID:20938095

  3. Potential role of autophagy in the bactericidal activity of human PMNs for Bacillus anthracis.

    Science.gov (United States)

    Ramachandran, Girish; Gade, Padmaja; Tsai, Pei; Lu, Wuyuan; Kalvakolanu, Dhananjaya V; Rosen, Gerald M; Cross, Alan S

    2015-12-01

    Bacillus anthracis, the causative agent of anthrax, is acquired by mammalian hosts from the environment, as quiescent endospores. These endospores must germinate inside host cells, forming vegetative bacilli, before they can express the virulence factors that enable them to evade host defenses and disseminate throughout the body. While the role of macrophages and dendritic cells in this initial interaction has been established, the role of polymorphonuclear leukocytes (PMNs) has not been adequately defined. We discovered that while B. anthracis 34F2 Sterne endospores germinate poorly within non-activated human PMNs, these phagocytes exhibit rapid microbicidal activity toward the outgrown vegetative bacilli, independent of superoxide and nitric oxide. These findings suggest that a non-free radical pathway kills B. anthracis bacilli. We also find in PMNs an autophagic mechanism of bacterial killing based on the rapid induction of LC-3 conversion, beclin-1 expression, sequestosome 1 (SQSTM1) degradation and inhibition of bactericidal activity by the inhibitor, 3-methyladenine. These findings extend to PMNs an autophagic bactericidal mechanism previously described for other phagocytes. PMID:26424808

  4. An investigation of the bactericidal activity of selected essential oils to Aeromonas spp.

    Science.gov (United States)

    Starliper, Clifford E.; Ketolab, Henry G.; Noyes, Andrew D.; Schill, William B.; Henson, Fred G.; Chalupnicki, Marc A.; Dittman, Dawn E.

    2015-01-01

    Diseases of fishes caused by Aeromonas spp. are common, have broad host ranges and may cause high mortality. Treatments for captive-reared populations using antimicrobials are limited with concerns for bacterial resistance development and environmental dissemination. This study was done to determine if selected plant-derived essential oils were bactericidal to Aeromonas spp. Initially, twelve essential oils were evaluated using a disk diffusion assay to an isolate of A. salmonicida subsp. salmonicida, cause of fish furunculosis. The greatest zones of inhibition were obtained with oils of cinnamon Cinnamomum cassia, oregano Origanum vulgare, lemongrass Cymbopogon citratus and thyme Thymus vulgaris. Minimum bactericidal concentrations (MBC’s) were determined for these four oils, Allimed® (garlic extract, Allium sativum) and colloidal silver to sixty-nine isolates representing nine Aeromonas spp. The lowest mean MBC’s (0.02 to 0.04%) were obtained with three different sources of cinnamon oil. MBC’s for three sources of oregano and lemongrass oils ranged from 0.14 to 0.30% and 0.10 to 0.65%, respectively, and for two thyme oils were 2.11 and 2.22%. The highest concentration (5%) of Allimed® tested resulted in MBC’s to twelve isolates. A concentration of silver greater than 15 mg/L would be required to determine MBC’s for all but one isolate

  5. Superior bactericidal activity of SDS capped silver nanoparticles: Synthesis and characterization

    International Nuclear Information System (INIS)

    Silver nanoparticles were synthesized through UV photo-reduction of silver nitrate aqueous solution, containing ethanol and sodium dodecyl sulfate (SDS) using an UV digester equipped with high pressure mercury lamp of 500 W. The synthesized nanoparticles were characterized by UV-vis spectroscopy (UV-vis), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The formation of silver nanoparticles was confirmed from the appearance of surface plasmon absorption maxima at 418 nm. TEM showed the spherical nanoparticles with size in 23-67 nm (average 45 ± 10 nm). The silver nanoparticles were stable for more than 8 months. The antibacterial activity of these SDS capped silver nanoparticles was tested using Pseudomonas aeruginosa as a model strain for gram-negative bacteria. SDS capped silver nanoparticles exhibit a much higher bactericidal activity compared to silver nanoparticles capped with other capping agents. Even at a low silver nanoparticle concentration of 5 μg/ml, complete inhibition of 107 colony forming units (CFU) was achieved with SDS capped silver nanoparticles. This concentration is much lower than the values reported by other authors. This enhanced bactericidal activity is attributed to much efficient transport of silver nanoparticles by SDS to the outer membrane of cell wall compared to the other capping agents and have a better interaction of nanoparticles with the cell.

  6. Synthesis and evaluation of bactericidal properties of CuO nanoparticles against Aeromonas hydrophila

    Directory of Open Access Journals (Sweden)

    Sayedeh Fatemeh Shaffiey

    2014-04-01

    Full Text Available   Objective(s: CuO is one of the most important transition metal oxides due to its captivating properties. It is used in various technological applications such as high critical temperature superconductors, gas sensors, in photoconductive applications, and so on. Recently, it has been used as an antimicrobial agent against various bacterial species.   Materials and Methods: Here, we synthesized CuO nanoparticles (NPs and explored the antibacterial activity of CuO NPs preparation. Results: Single crystalline nanoparticles of copper oxide having almost uniform particle size of 5-6 nm has been synthesized by a facile and versatile route. XRD spectra confirmed the formation of single phase CuO NPs. Transmission electron microscopy results corroborate well with XRD results. The technique employed is free from toxic solvents, organics and amines, is based on a simple reaction of copper sulfate and de-ionized water (DI, and their bactericidal effects against of Aeromonas hydrophila ATCC 7966T bacteria were investigated. Minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC with liquid culture for all of the Aeromonas hydrophila culture Medias was done. Conclusion: Present study confirms that Copper oxide nanoparticles have great promise as antimicrobial agent against Aeromonas hydrophila

  7. Drug delivery property, bactericidal property and cytocompatibility of magnetic mesoporous bioactive glass

    International Nuclear Information System (INIS)

    A multifunctional magnetic mesoporous bioactive glass (MMBG) has been widely used for a drug delivery system, but its biological properties have been rarely reported. Herein, the effects of mesopores and Fe3O4 nanoparticles on drug loading–release property, bactericidal property and biocompatibility have been investigated by using mesoporous bioactive glass (MBG) and non-mesoporous bioactive glass (NBG) as control samples. Both MMBG and MBG have better drug loading efficiency than NBG because they possess ordered mesoporous channels, big specific surface areas and high pore volumes. As compared with MBG, the Fe3O4 nanoparticles in MMBG not only provide magnetic property, but also improve sustained drug release property. For gentamicin-loaded MMBG (Gent-MMBG), the sustained release of gentamicin and the Fe3O4 nanoparticles minimize bacterial adhesion significantly and prevent biofilm formation against Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis). Moreover, the magnetic Fe3O4 nanoparticles in MMBG can promote crucial cell functions such as cell adhesion, spreading and proliferation. The excellent biocompatibility and drug delivery property of MMBG suggest that Gent-MMBG has great potentials for treatment of implant-associated infections. - Highlights: • Multifunctional magnetic mesoporous bioactive glass is fabricated. • The bioactive glass has great biocompatibility. • The bioactive glass exhibits high drug loading–release properties. • The drug delivery system has bactericidal property. • Magnetic particles improve cell adhesion, spreading and proliferation

  8. Understanding bactericidal performance on ambient light activated TiO2-InVO4 nanostructured films

    Science.gov (United States)

    He, Ziming; Xu, Qingchi; Yang Tan, Timothy Thatt

    2011-12-01

    TiO2-InVO4 nanostructured films were coated onto glass substrates and systematically investigated for their bactericidal activities using Escherichia coli (E. coli) as the model bacterium under ambient light illumination. The uniform TiO2-InVO4 nanostructured films were prepared using titanium isopropoxide (TTIP) as the precursor via a simple sol-gel approach. Polyethylenimine (PEI) was used as a surfactant to ensure uniform dispersion of InVO4 and a sacrificial pore-inducing agent, generating nanostructured films. Compared to unmodified TiO2 film, the current TiO2-InVO4 films exhibited enhanced bactericidal activities under ambient light illumination. Bacterial cell ``photo-fixation'' was demonstrated to be crucial in enhancing the bactericidal activity. A bacterial-nanostructured surface interaction mechanism was proposed for the current ambient-light activated nanostructured film.TiO2-InVO4 nanostructured films were coated onto glass substrates and systematically investigated for their bactericidal activities using Escherichia coli (E. coli) as the model bacterium under ambient light illumination. The uniform TiO2-InVO4 nanostructured films were prepared using titanium isopropoxide (TTIP) as the precursor via a simple sol-gel approach. Polyethylenimine (PEI) was used as a surfactant to ensure uniform dispersion of InVO4 and a sacrificial pore-inducing agent, generating nanostructured films. Compared to unmodified TiO2 film, the current TiO2-InVO4 films exhibited enhanced bactericidal activities under ambient light illumination. Bacterial cell ``photo-fixation'' was demonstrated to be crucial in enhancing the bactericidal activity. A bacterial-nanostructured surface interaction mechanism was proposed for the current ambient-light activated nanostructured film. Electronic supplementary information (ESI) available: Photocatalytic activity test procedure and results, AFM images, EDX results, LSCM images, and wettability results. See DOI: 10.1039/c1nr11126d

  9. Mechanisms of Bactericidal Action of Cinnamaldehyde against Listeria monocytogenes and of Eugenol against L. monocytogenes and Lactobacillus sakei

    OpenAIRE

    Gill, Alexander O.; Holley, Richard A.

    2004-01-01

    The spice oil components eugenol and cinnamaldehyde possess activity against both gram-positive and gram-negative bacteria, but the mechanisms of action remain obscure. In broth media at 20°C, 5 mM eugenol or 30 mM cinnamaldehyde was bactericidal (>1-log reduction in the number of CFU per milliliter in 1 h) to Listeria monocytogenes. At a concentration of 6 mM eugenol was bactericidal to Lactobacillus sakei, but treatment with 0.5 M cinnamaldehyde had no significant effect. To investigate the...

  10. Postantibiotic effect assessments for antibiotics exhibiting a wide range of bactericidal activities by using a modified total-cell-counting method.

    OpenAIRE

    Li, R. C.; S.W. Lee

    1997-01-01

    We recently described a total-cell-counting method for postantibiotic effect (PAE) assessments that performs well with weakly bactericidal antibiotics. This note presents a modified method for the study of PAE with extended capability to cover a broad range of bactericidal activities.

  11. Synthesis of poly(amidoamine-dendrimer-silver nanoparticles composite for application as bactericides

    Directory of Open Access Journals (Sweden)

    Shahla Namazkar

    2014-04-01

    Full Text Available As awareness of sanitation, disease transmission factors and personal protection increases, researchers have focused on developing materials with antibacterial properties. Silver-PAMAM-dendrimer has unique antibacterial properties that make it an ideal candidate for medical applications. In this study, poly (amidoamine (PAMAM dendrimers from Generations 0.5- 4.0 were synthesized using divergent methods. Silver was combined with PAMAM dendrimers from the Generation 2.0, 3.0 and 4.0 to form colloidal solutions. The antimicrobial capabilities of Silver-PAMAM-dendrimer (Generation 2.0 were tested against four types of gram positive and negative bacteria. Its bactericidal activities were revealed for all four types of bacteria that could not grow in samples containing 600 ppm of Silver-PAMAM-dendrimer (Generation 2.0.

  12. In-vitro bactericidal activity of maggots of the green blowfly (Lucilia sericata

    Directory of Open Access Journals (Sweden)

    Daeschlein, Georg

    2006-08-01

    Full Text Available Maggots of Lucilia sericata are used as an alternative to surgical intervention and long-term antiseptic therapy for the treatment of chronic wounds. To quantify the bactericidal effect of secretions from larvae, an in-vitro test model based on the modified European quantitative suspension test (EN 1040 was developed, in which a co-culture of maggots and bacteria (Micrococcus luteus, Escherichia coli, Methicillin-sensitive Staphylococcus aureus in tryptic soy broth was tested. The numbers of bacterial colonies with and without maggot exposure were compared after 24, 48, and 72 h of exposure. The mean log10 reduction factor (RF for bacterial elimination per maggot was > 4 at all examined times for all tested bacteria. Thus, maggot secretion fulfilled the required definitions of an antiseptic. In addition, maggot's ability of ingesting bacteria was also evaluated. Maggots contained viable bacteria after 48 h of contact with the respective organisms. These maggots also continued excreting bacteria.

  13. Bactericidal and virucidal mechanisms in the alkaline disinfection of compost using calcium lime and ash.

    Science.gov (United States)

    Hijikata, Nowaki; Tezuka, Rui; Kazama, Shinobu; Otaki, Masahiro; Ushijima, Ken; Ito, Ryusei; Okabe, Satoshi; Sano, Daisuke; Funamizu, Naoyuki

    2016-10-01

    In the present study, the bactericidal and virucidal mechanisms in the alkaline disinfection of compost with calcium lime and ash were investigated. Two indicator microorganisms, Escherichia coli and MS2 coliphage, were used as surrogates for enteric pathogens. The alkaline-treated compost with calcium oxide (CaO) or ash resulted primarily in damage to the outer membrane and enzyme activities of E. coli. The alkaline treatment of compost also led to the infectivity loss of the coliphage because of the partial capsid damage and RNA exteriorization due to a raised pH, which is proportional to the amount of alkaline agents added. These results indicate that the alkaline treatment of compost using calcium oxide and ash is effective and can contribute to the safe usage of compost from a mixing type dry toilet. PMID:27562698

  14. Modification of medical grade PVC with N-vinylimidazole to obtain bactericidal surface

    Science.gov (United States)

    Meléndez-Ortiz, H. Iván; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Jiménez-Páez, Víctor M.; Bucio, Emilio

    2016-02-01

    N-vinylimidazole (VIm) was grafted onto medical-grade poly(vinyl chloride) (PVC) catheters in order to provide a bactericidal surface that make them less susceptible to microbial colonization. The grafting of VIm was carried out by means of gamma rays using the direct method, which demonstrated to be an efficient and fast procedure for obtaining PVC-g-VIm copolymers. These copolymers could be quaternized in a second step using methyl iodide (CH3I). The effects of solvent nature, absorbed dose, and monomer concentration on the grafting yield were investigated. Modified PVC catheters were characterized by means of Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TGA), and swelling studies. PVC-g-VIm copolymers both before and after quaternization showed good hemocompatibility, while quaternization was required to inhibit the growth of Staphylococcus aureus.

  15. Calcium and Zinc Containing Bactericidal Glass Coatings for Biomedical Metallic Substrates

    Directory of Open Access Journals (Sweden)

    Leticia Esteban-Tejeda

    2014-07-01

    Full Text Available The present work presents new bactericidal coatings, based on two families of non-toxic, antimicrobial glasses belonging to B2O3–SiO2–Na2O–ZnO and SiO2–Na2O–Al2O3–CaO–B2O3 systems. Free of cracking, single layer direct coatings on different biomedical metallic substrates (titanium alloy, Nb, Ta, and stainless steel have been developed. Thermal expansion mismatch was adjusted by changing glass composition of the glass type, as well as the firing atmosphere (air or Ar according to the biomedical metallic substrates. Formation of bubbles in some of the glassy coatings has been rationalized considering the reactions that take place at the different metal/coating interfaces. All the obtained coatings were proven to be strongly antibacterial versus Escherichia coli (>4 log.

  16. 11. Bactericidal Activity of Photocatalytic TiO2 Excited by Low Intensity Pulsed Ultrasound (LIPUS): An In Vitro Study.

    Science.gov (United States)

    Noguchi, Chieko; Koseki, Hironobu

    2016-08-01

    Photocatalysis with anatase-type titanium dioxide (TiO2) under ultraviolet has a well-recognized bactericidal effect. The purpose of the present study was to evaluate the photocatalytic bactericidal effects of TiO2 on Staphylococcus epidermidis (ATCC35984) caused by Low Intensity Pulsed Ultrasound (LIPUS) associated with bio-implant-related infections. The photocatalytic properties of the TiO2 films were confirmed by the degradation of an aqueous solution of methylene blue. The disks were seeded with cultured Staphylococcus epidermidis and irradiated by LIPUS. The bactericidal effect of the TiO2 films was evaluated by counting the surviving colonies. The viability of the bacteria on the photocatalytic TiO2 film coated titanium was suppressed significantly to 63% after 2 hours of LIPUS treatment (P < 0.05). The photocatalytic bactericidal effect of TiO2 under LIPUS is useful for sterilizing the contaminated and infected surfaces of metal bio-implants. PMID:27441772

  17. Microwave, sonochemical and combustion synthesized CuO nanostructures and their electrical and bactericidal properties

    International Nuclear Information System (INIS)

    Highlights: •CuO nanoleaves synthesized by CTAB-assisted hydrothermal method. •CuO nanodiscs synthesized by CTAB-assisted sonochemical method. •Combustion synthesized CuO is highly porous. •Synthetic method and morphology influence CuO bactericidal activity. -- Abstract: Cetyltrimethylammonium bromide (CTAB)-assisted microwave synthesis of CuO provides nanoleaves and in the absence of CTAB the shape of CuO is irregular. Sonochemical synthesis of CuO using CTAB gives nanodiscs whereas irregularly shaped flake-like structure is obtained without CTAB. Combustion synthesized CuO is highly porous with innumerable large holes. CTAB does not provide any structure in combustion synthesis. Transmission electron micrographs (TEM) display the constituent nanoparticles of microwave and sonochemically synthesized CuO. The powder X-ray diffractogram (XRD) shows the sample obtained by sonochemical method in the absence of CTAB as a mixture of monoclinic CuO, cubic Cu2O, and orthorhombic Cu(OH)2. But the rest of the samples are pure CuO in monoclinic phase. The selected area electron diffractograms (SAED) of the microwave and sonochemically synthesized samples, in the presence as well as in the absence of CTAB, confirm the monoclinic phase of CuO and indicates the presence of amorphous CuO in traces. All the samples are characteristic of Fourier Transform infrared (FT-IR) Cu–O stretching frequencies. The method of synthesis and also the morphology influence the electrical properties as well as the bactericidal activity of CuO

  18. Oxidative DNA damage caused by pulsed discharge with cavitation on the bactericidal function

    International Nuclear Information System (INIS)

    Plasma-based techniques are expected to have practical use for wastewater purification with a potential for killing contaminated microorganisms and degrading recalcitrant materials. In the present study, we analysed oxidative DNA damage in bacterial cells treated by the plasma to unveil its mechanisms in the bactericidal process. Escherichia coli cell suspension was exposed to the plasma induced by applying an alternating-current voltage of about 1 kV with bubbling formed by water-cavitation, termed pulsed discharge with cavitation. Chromosomal DNA damage, such as double strand break (DSB) and oxidative base lesions, increased proportionally with the applied energy, as determined by electrophoretic and mass spectrometric analyses. Among the base lesions identified, the yields of 8-hydroxyguanine (8-OH-G) and 5-hydroxycytosine (5-OH-C) in chromosomal DNA increased by up to 4- and 15-fold, respectively, compared to untreated samples. The progeny DNA sequences, derived from plasmid DNA exposed to the plasma, indicated that the production rate of 5-OH-C exceeded that of 8-OH-G, as G:C to A:T transitions accounted for 65% of all base changes, but only a few G:C to T:A transversions were observed. The cell viabilities of E. coli cells decreased in direct proportion to increases in the applied energy. Therefore, the plasma-induced bactericidal mechanism appears to relate to oxidative damage caused to bacterial DNA. These results were confirmed by observing the generation of hydroxyl radicals and hydrogen peroxide molecules following the plasma exposure. We also compared our results with the plasma to those obtained with 137Cs γ-rays, as a well-known ROS generator to confirm the DNA-damaging mechanism involved. (paper)

  19. Oxidative DNA damage caused by pulsed discharge with cavitation on the bactericidal function

    Science.gov (United States)

    Kudo, Ken-ichi; Ito, Hironori; Ihara, Satoshi; Terato, Hiroaki

    2015-09-01

    Plasma-based techniques are expected to have practical use for wastewater purification with a potential for killing contaminated microorganisms and degrading recalcitrant materials. In the present study, we analysed oxidative DNA damage in bacterial cells treated by the plasma to unveil its mechanisms in the bactericidal process. Escherichia coli cell suspension was exposed to the plasma induced by applying an alternating-current voltage of about 1 kV with bubbling formed by water-cavitation, termed pulsed discharge with cavitation. Chromosomal DNA damage, such as double strand break (DSB) and oxidative base lesions, increased proportionally with the applied energy, as determined by electrophoretic and mass spectrometric analyses. Among the base lesions identified, the yields of 8-hydroxyguanine (8-OH-G) and 5-hydroxycytosine (5-OH-C) in chromosomal DNA increased by up to 4- and 15-fold, respectively, compared to untreated samples. The progeny DNA sequences, derived from plasmid DNA exposed to the plasma, indicated that the production rate of 5-OH-C exceeded that of 8-OH-G, as G:C to A:T transitions accounted for 65% of all base changes, but only a few G:C to T:A transversions were observed. The cell viabilities of E. coli cells decreased in direct proportion to increases in the applied energy. Therefore, the plasma-induced bactericidal mechanism appears to relate to oxidative damage caused to bacterial DNA. These results were confirmed by observing the generation of hydroxyl radicals and hydrogen peroxide molecules following the plasma exposure. We also compared our results with the plasma to those obtained with 137Cs γ-rays, as a well-known ROS generator to confirm the DNA-damaging mechanism involved.

  20. Microwave, sonochemical and combustion synthesized CuO nanostructures and their electrical and bactericidal properties

    Energy Technology Data Exchange (ETDEWEB)

    Karunakaran, C., E-mail: karunakaranc@rediffmail.com; Manikandan, G.; Gomathisankar, P.

    2013-12-15

    Highlights: •CuO nanoleaves synthesized by CTAB-assisted hydrothermal method. •CuO nanodiscs synthesized by CTAB-assisted sonochemical method. •Combustion synthesized CuO is highly porous. •Synthetic method and morphology influence CuO bactericidal activity. -- Abstract: Cetyltrimethylammonium bromide (CTAB)-assisted microwave synthesis of CuO provides nanoleaves and in the absence of CTAB the shape of CuO is irregular. Sonochemical synthesis of CuO using CTAB gives nanodiscs whereas irregularly shaped flake-like structure is obtained without CTAB. Combustion synthesized CuO is highly porous with innumerable large holes. CTAB does not provide any structure in combustion synthesis. Transmission electron micrographs (TEM) display the constituent nanoparticles of microwave and sonochemically synthesized CuO. The powder X-ray diffractogram (XRD) shows the sample obtained by sonochemical method in the absence of CTAB as a mixture of monoclinic CuO, cubic Cu{sub 2}O, and orthorhombic Cu(OH){sub 2}. But the rest of the samples are pure CuO in monoclinic phase. The selected area electron diffractograms (SAED) of the microwave and sonochemically synthesized samples, in the presence as well as in the absence of CTAB, confirm the monoclinic phase of CuO and indicates the presence of amorphous CuO in traces. All the samples are characteristic of Fourier Transform infrared (FT-IR) Cu–O stretching frequencies. The method of synthesis and also the morphology influence the electrical properties as well as the bactericidal activity of CuO.

  1. Drug delivery property, bactericidal property and cytocompatibility of magnetic mesoporous bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yi-Zhuo [The Education Ministry Key Lab of Resource Chemistry, Shanghai Normal University, Shanghai 200234 (China); Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Li, Yang [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Yu, Xi-Bin [The Education Ministry Key Lab of Resource Chemistry, Shanghai Normal University, Shanghai 200234 (China); Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Liu, Li-Na [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Zhu, Zhen-An, E-mail: zhuzhenan2006@126.com [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Guo, Ya-Ping, E-mail: ypguo@shnu.edu.cn [The Education Ministry Key Lab of Resource Chemistry, Shanghai Normal University, Shanghai 200234 (China); Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China)

    2014-08-01

    A multifunctional magnetic mesoporous bioactive glass (MMBG) has been widely used for a drug delivery system, but its biological properties have been rarely reported. Herein, the effects of mesopores and Fe{sub 3}O{sub 4} nanoparticles on drug loading–release property, bactericidal property and biocompatibility have been investigated by using mesoporous bioactive glass (MBG) and non-mesoporous bioactive glass (NBG) as control samples. Both MMBG and MBG have better drug loading efficiency than NBG because they possess ordered mesoporous channels, big specific surface areas and high pore volumes. As compared with MBG, the Fe{sub 3}O{sub 4} nanoparticles in MMBG not only provide magnetic property, but also improve sustained drug release property. For gentamicin-loaded MMBG (Gent-MMBG), the sustained release of gentamicin and the Fe{sub 3}O{sub 4} nanoparticles minimize bacterial adhesion significantly and prevent biofilm formation against Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis). Moreover, the magnetic Fe{sub 3}O{sub 4} nanoparticles in MMBG can promote crucial cell functions such as cell adhesion, spreading and proliferation. The excellent biocompatibility and drug delivery property of MMBG suggest that Gent-MMBG has great potentials for treatment of implant-associated infections. - Highlights: • Multifunctional magnetic mesoporous bioactive glass is fabricated. • The bioactive glass has great biocompatibility. • The bioactive glass exhibits high drug loading–release properties. • The drug delivery system has bactericidal property. • Magnetic particles improve cell adhesion, spreading and proliferation.

  2. Two approaches to form antibacterial surface: Doping with bactericidal element and drug loading

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Bioactive materials with rate-controlled release of antibacterial agent. • Ag+ ion release from TiCaPCON-Ag films depended on Ag content. • TiCaPCON-coated Ti network structure with blind pores loaded with co-amoxiclav. • Strong bactericidal effect of drug-loaded samples. • Antibacterial yet biocompatible and bioactive surfaces. - Abstract: Two approaches (surface doping with bactericidal element and loading of antibiotic into specially formed surface microcontainers) to the fabrication of antibacterial yet biocompatible and bioactive surfaces are described. A network structure with square-shaped blind pores of 2.6 ± 0.6 × 10−3 mm3 for drug loading was obtained by selective laser sintering (SLS). The SLS-fabricated samples were loaded with 0.03, 0.3, 2.4, and 4 mg/cm2 of co-amoxiclav (amoxicillin and clavulanic acid). Ag-doped TiCaPCON films with 0.4, 1.2, and 4.0 at.% of Ag were obtained by co-sputtering of composite TiC0.5-Ca3(PO4)2 and metallic Ag targets. The surface structure of SLS-prepared samples and cross-sectional morphology of TiCaPCON-Ag films were studied by scanning electron microscopy. The through-thickness of Ag distribution in the TiCaPCON-Ag films was obtained by glow discharge optical emission spectroscopy. The kinetics of Ag ion release in normal saline solution was studied using inductively coupled plasma mass spectrometry. Bacterial activity of the samples was evaluated against S. epidermidis, S. aureus, and K. pneum. ozaenae using the agar diffusion test and photometric method by controlling the variation of optical density of the bacterial suspension over time. Cytocompatibility of the Ag-doped TiCaPCON films was observed in vitro using chondrocytic and MC3T3-E1 osteoblastic cells. The viability and proliferation of chondrocytic cells were determined using the MTS assay and PicoGreen assay tests, respectively. The alkaline phosphatase (ALP) activity of the SLS-fabricated samples loaded with

  3. Two approaches to form antibacterial surface: Doping with bactericidal element and drug loading

    Energy Technology Data Exchange (ETDEWEB)

    Sukhorukova, I.V.; Sheveyko, A.N.; Kiryukhantsev-Korneev, Ph.V. [National University of Science and Technology “MISIS”, Leninsky pr. 4, Moscow 119049 (Russian Federation); Anisimova, N.Y.; Gloushankova, N.A.; Zhitnyak, I.Y. [N.N Blokhin Russian Cancer Research Center of RAMS, Kashirskoe shosse 24, Moscow 115478 (Russian Federation); Benesova, J. [Institute of Experimental Medicine of the ASCR, Vídenska 1083, Prague 14220 (Czech Republic); Institute of Biophysics, 2nd Faculty of Medicine, Charles University in Prague, V Uvalu 84, Prague 15006 (Czech Republic); Amler, E. [Institute of Experimental Medicine of the ASCR, Vídenska 1083, Prague 14220 (Czech Republic); Faculty of Biomedical Engineering, Czech Technical University in Prague (Czech Republic); Shtansky, D.V., E-mail: shtansky@shs.misis.ru [National University of Science and Technology “MISIS”, Leninsky pr. 4, Moscow 119049 (Russian Federation)

    2015-03-01

    Graphical abstract: - Highlights: • Bioactive materials with rate-controlled release of antibacterial agent. • Ag{sup +} ion release from TiCaPCON-Ag films depended on Ag content. • TiCaPCON-coated Ti network structure with blind pores loaded with co-amoxiclav. • Strong bactericidal effect of drug-loaded samples. • Antibacterial yet biocompatible and bioactive surfaces. - Abstract: Two approaches (surface doping with bactericidal element and loading of antibiotic into specially formed surface microcontainers) to the fabrication of antibacterial yet biocompatible and bioactive surfaces are described. A network structure with square-shaped blind pores of 2.6 ± 0.6 × 10{sup −3} mm{sup 3} for drug loading was obtained by selective laser sintering (SLS). The SLS-fabricated samples were loaded with 0.03, 0.3, 2.4, and 4 mg/cm{sup 2} of co-amoxiclav (amoxicillin and clavulanic acid). Ag-doped TiCaPCON films with 0.4, 1.2, and 4.0 at.% of Ag were obtained by co-sputtering of composite TiC{sub 0.5}-Ca{sub 3}(PO{sub 4}){sub 2} and metallic Ag targets. The surface structure of SLS-prepared samples and cross-sectional morphology of TiCaPCON-Ag films were studied by scanning electron microscopy. The through-thickness of Ag distribution in the TiCaPCON-Ag films was obtained by glow discharge optical emission spectroscopy. The kinetics of Ag ion release in normal saline solution was studied using inductively coupled plasma mass spectrometry. Bacterial activity of the samples was evaluated against S. epidermidis, S. aureus, and K. pneum. ozaenae using the agar diffusion test and photometric method by controlling the variation of optical density of the bacterial suspension over time. Cytocompatibility of the Ag-doped TiCaPCON films was observed in vitro using chondrocytic and MC3T3-E1 osteoblastic cells. The viability and proliferation of chondrocytic cells were determined using the MTS assay and PicoGreen assay tests, respectively. The alkaline phosphatase (ALP

  4. Antibiotic Bactericidal Activity Is Countered by Maintaining pH Homeostasis in Mycobacterium smegmatis.

    Science.gov (United States)

    Bartek, I L; Reichlen, M J; Honaker, R W; Leistikow, R L; Clambey, E T; Scobey, M S; Hinds, A B; Born, S E; Covey, C R; Schurr, M J; Lenaerts, A J; Voskuil, M I

    2016-01-01

    Antibiotics target specific biosynthetic processes essential for bacterial growth. It is intriguing that several commonalities connect the bactericidal activity of seemingly disparate antibiotics, such as the numerous conditions that confer broad-spectrum antibiotic tolerance. Whether antibiotics kill in a manner unique to their specific targets or by a universal mechanism is a critical and contested subject. Herein, we demonstrate that the bactericidal activity of diverse antibiotics against Mycobacterium smegmatis and four evolutionarily divergent bacterial pathogens was blocked by conditions that worked to maintain intracellular pH homeostasis. Single-cell pH analysis demonstrated that antibiotics increased the cytosolic pH of M. smegmatis, while conditions that promoted proton entry into the cytosol prevented intracellular alkalization and antibiotic killing. These findings led to a hypothesis that posits antibiotic lethality occurs when antibiotics obstruct ATP-consuming biosynthetic processes while metabolically driven proton efflux is sustained despite the loss of proton influx via ATP synthase. Consequently, without a concomitant reduction in respiratory proton efflux, cell death occurs due to intracellular alkalization. Our findings indicate the effects of antibiotics on pH homeostasis should be considered a potential mechanism contributing to antibiotic lethality. IMPORTANCE Since the discovery of antibiotics, mortality due to bacterial infection has decreased dramatically. However, infections from difficult to treat bacteria such as Mycobacterium tuberculosis and multidrug-resistant pathogens have been on the rise. An understanding of the cascade of events that leads to cell death downstream of specific drug-target interactions is not well understood. We have discovered that killing by several classes of antibiotics was stopped by maintaining pH balance within the bacterial cell, consistent with a shared mechanism of antibiotic killing. Our findings

  5. Two approaches to form antibacterial surface: Doping with bactericidal element and drug loading

    Science.gov (United States)

    Sukhorukova, I. V.; Sheveyko, A. N.; Kiryukhantsev-Korneev, Ph. V.; Anisimova, N. Y.; Gloushankova, N. A.; Zhitnyak, I. Y.; Benesova, J.; Amler, E.; Shtansky, D. V.

    2015-03-01

    Two approaches (surface doping with bactericidal element and loading of antibiotic into specially formed surface microcontainers) to the fabrication of antibacterial yet biocompatible and bioactive surfaces are described. A network structure with square-shaped blind pores of 2.6 ± 0.6 × 10-3 mm3 for drug loading was obtained by selective laser sintering (SLS). The SLS-fabricated samples were loaded with 0.03, 0.3, 2.4, and 4 mg/cm2 of co-amoxiclav (amoxicillin and clavulanic acid). Ag-doped TiCaPCON films with 0.4, 1.2, and 4.0 at.% of Ag were obtained by co-sputtering of composite TiC0.5-Ca3(PO4)2 and metallic Ag targets. The surface structure of SLS-prepared samples and cross-sectional morphology of TiCaPCON-Ag films were studied by scanning electron microscopy. The through-thickness of Ag distribution in the TiCaPCON-Ag films was obtained by glow discharge optical emission spectroscopy. The kinetics of Ag ion release in normal saline solution was studied using inductively coupled plasma mass spectrometry. Bacterial activity of the samples was evaluated against S. epidermidis, S. aureus, and K. pneum. ozaenae using the agar diffusion test and photometric method by controlling the variation of optical density of the bacterial suspension over time. Cytocompatibility of the Ag-doped TiCaPCON films was observed in vitro using chondrocytic and MC3T3-E1 osteoblastic cells. The viability and proliferation of chondrocytic cells were determined using the MTS assay and PicoGreen assay tests, respectively. The alkaline phosphatase (ALP) activity of the SLS-fabricated samples loaded with co-amoxiclav was also studied. The obtained results showed that the moderate bacteriostatic effect of the Ag-doped TiCaPCON films is mainly manifested in the change of bacterial colony morphology and optical densities of bacteria suspensions. In contrast, the SLS-prepared samples showed a very rapid initial drug release resulting in strong bactericidal effect just from the start of the

  6. The bactericidal effect of carbon nanotube/agar composites irradiated with near-infrared light on Streptococcus mutans

    International Nuclear Information System (INIS)

    Dental caries are mainly associated with oral pathogens, and Streptococcus mutans is a primary cariogenic organism. Many methods have been established to eliminate S. mutans from the oral cavity. This study aimed to evaluate the effect of carbon nanotube (CNT)/agar composites irradiated with near-infrared (NIR) light on S. mutans, as a potential photothermal antimicrobial nanotherapy. A colony-forming unit assay clearly showed that CNT/agar composites attain bactericidal activity after NIR light irradiation; this bactericidal activity is higher than that of graphite (GP)/agar and activated carbon (AC)/agar composites. Furthermore, it was observed that longer irradiation times immobilized S. mutans in the CNT/agar composite.

  7. In vitro bactericidal and fungicidal activities of various extracts of saffron (Crocus sativus L. stigmas from Jammu & Kashmir, India

    Directory of Open Access Journals (Sweden)

    Syed Muzaffar

    2016-12-01

    Full Text Available Antimicrobial activities of methanolic and petroleum ether extracts of Croccus sativus L. (saffron stigmas, were tested against various bacterial strains (Proteus vulgaris, Klebsiella pneumonia, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli and fungi (Candida albicans, Aspergillus niger and Aspergillus fumigatus by agar well diffusion method. Minimal inhibitory concentration and minimum bactericidal and fungicidal concentration values of each active extract were also determined. The results showed a strong activity of the petroleum ether and methanolic extracts of saffron stigmas against bacteria and fungi used as test organisms. The results of different antimicrobial assays also indicate that the extracts had significantly higher bactericidal than fungicidal activities (p < 0.05. The results suggest that these extracts can be used in pharmaceutical and food formulations for inhibiting pathogenic bacterial and fungal species.

  8. The bactericidal effect of carbon nanotube/agar composites irradiated with near-infrared light on Streptococcus mutans

    Energy Technology Data Exchange (ETDEWEB)

    Akasaka, Tsukasa, E-mail: akasaka@den.hokudai.ac.jp [Graduate School of Dental Medicine, Hokkaido University, Kita13 Nishi7, Kita-ku, Sapporo 060-8586 (Japan); Matsuoka, Makoto [Graduate School of Dental Medicine, Hokkaido University, Kita13 Nishi7, Kita-ku, Sapporo 060-8586 (Japan); Hashimoto, Takeshi [Meijo Nano Carbon Co. Ltd., Otsubashi bldg. 4F, 3-4-10 Marunouchi, Naka-ku, Nagoya 460-0002 (Japan); Abe, Shigeaki; Uo, Motohiro; Watari, Fumio [Graduate School of Dental Medicine, Hokkaido University, Kita13 Nishi7, Kita-ku, Sapporo 060-8586 (Japan)

    2010-10-15

    Dental caries are mainly associated with oral pathogens, and Streptococcus mutans is a primary cariogenic organism. Many methods have been established to eliminate S. mutans from the oral cavity. This study aimed to evaluate the effect of carbon nanotube (CNT)/agar composites irradiated with near-infrared (NIR) light on S. mutans, as a potential photothermal antimicrobial nanotherapy. A colony-forming unit assay clearly showed that CNT/agar composites attain bactericidal activity after NIR light irradiation; this bactericidal activity is higher than that of graphite (GP)/agar and activated carbon (AC)/agar composites. Furthermore, it was observed that longer irradiation times immobilized S. mutans in the CNT/agar composite.

  9. MINIMUM INHIBITORY AND BACTERICIDAL CONCENTRATIONS OF THEAFLAVIN AND SYNGERGISTIC COMBINATIONS WITH EPICATECHIN AND QUERCETIN AGAINST CLINICAL ISOLATES OF STENOTROPHOMONAS MALTOPHILIA

    Directory of Open Access Journals (Sweden)

    Stephen Haswell

    2012-04-01

    Full Text Available Stenotrophomonas maltophilia is an important nosocomial pathogen with intrinsic resistance to multiple antibiotics. Previous investigations have shown flavanols from black tea to possess antibacterial activity. This study describes the determination of minimum inhibitory concentrations and minimum bactericidal concentration for theaflavin independently and in formulations with the polyphenols epicatechin and quercetin against nine clinical isolates of Stenotrophomonas maltophilia and the control isolate NCTC 130141 via the microtitre assay. The results demonstrate that theaflavin has strong antibacterial activity and also shows significant synergism with epicatechin and quercetin. The minimum inhibitory concentrations of the isolates range between 200-400 g/mL for theaflavin and 100-200 g/mL for both theaflavin:epicatechin and theaflavin:quercetin combinations. The minimum bactericidal concentrations were discovered to be a 2 fold increase on those of the minimum inhibitory concentrations. The research highlights the potential use of polyphenols for the clinical treatment of highly antibiotic resistant bacteria

  10. Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

    International Nuclear Information System (INIS)

    Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain

  11. Monoclonal antibodies against the iron regulated outer membrane Proteins of Acinetobacter baumannii are bactericidal

    Directory of Open Access Journals (Sweden)

    Goel Vikas

    2001-08-01

    Full Text Available Abstract Background Iron is an important nutrient required by all forms of life.In the case of human hosts,the free iron availability is 10-18M,which is far less than what is needed for the survival of the invading bacterial pathogen.To survive in such conditions, bacteria express new proteins in their outer membrane and also secrete iron chelators called siderophores. Results/ Discussion Acinetobacter baumannii ATCC 19606, a nosocomial pathogen which grows under iron restricted conditions, expresses four new outer membrane proteins,with molecular weight ranging from 77 kDa to 88 kDa, that are called Iron Regulated Outer Membrane Proteins (IROMPs. We studied the functional and immunological properties of IROMPs expressed by A.baumanii ATCC 19606.The bands corresponding to IROMPs were eluted from SDS-PAGE and were used to immunize BALB/c mice for the production of monoclonal antibodies. Hybridomas secreting specific antibodies against these IROMPs were selected after screening by ELISA and their reactivity was confirmed by Western Blot. The antibodies then generated belonged to IgM isotype and showed bactericidical and opsonising activities against A.baumanii in vitro.These antibodies also blocked siderophore mediated iron uptake via IROMPs in bacteria. Conclusion This proves that iron uptake via IROMPs,which is mediated through siderophores,may have an important role in the survival of A.baumanii inside the host,and helps establishing the infection.

  12. Antibodies with higher bactericidal activity induced by a Neisseria gonorrhoeae Rmp deletion mutant strain.

    Directory of Open Access Journals (Sweden)

    Guocai Li

    Full Text Available Neisseria gonorrhoeae (N. gonorrhoeae outer membrane protein reduction modifiable protein (Rmp has strong immunogenicity. However, anti-Rmp antibodies block rather than preserve the antibacterial effects of protective antibodies, which hampers the development of vaccines for gonococcal infections. We herein constructed an Rmp deletion mutant strain of N. gonorrhoeae by gene homologous recombination. The 261-460 nucleotide residues of Rmp gene amplified from N. gonorrhoeae WHO-A strain were replaced with a kanamycin-resistant Kan gene amplified from pET-28a. The resultant hybridized DNA was transformed into N. gonorrhoeae WHO-A strain. PCR was used to screen the colonies in which wild-type Rmp gene was replaced with a mutant gene fragment. Western blotting revealed that the Rmp deletion mutant strain did not express Rmp protein. Rmp deletion did not alter the morphological and Gram staining properties of the mutant strain that grew slightly more slowly than the wild-type one. Rmp gene mutated stably throughout 25 generations of passage. Antibody-mediated complement-dependent cytotoxicity assay indicated that the antibodies induced by the mutant strain had evidently higher bactericidal activities than those induced by the wild-type strain. Further modification of the Rmp deletion mutant strain is still required in the development of novel live attenuated vaccines for gonorrhea by Opa genes deletion or screening of phenotypic variant strains that do not express Opa proteins.

  13. Synthesis of nanosilver particles by reverse micelle method and study of their bactericidal properties

    Energy Technology Data Exchange (ETDEWEB)

    Tran Thi Ngoc Dung; Ngo Quoc Buu; Dang Viet Quang; Le Anh Bang; Nguyen Hoai Chau; Nguyen Thi Ly [Institute of Environmental Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay Distr., Hanoi (Viet Nam); Huynh Thi Ha [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay Distr., Hanoi (Viet Nam); Nguyen Vu Trung [National Institute for Infectious and Tropical Diseases, 1 Ton That Tung, Dong Da Distr., Hanoi (Viet Nam)], E-mail: ttndzung@yahoo.com, E-mail: buu_nq@yahoo.com

    2009-09-01

    Nanosilver particles have been synthesized by the reverse micelle method, where AgNO{sub 3} was used as a silver ions source, NaBH{sub 4} and quercetin - as reducing agents, CTAB, SDOSS and AOT- as surfactants, while the stabilizer was Vietnamese chitosan. Studying the factors influencing the process of nanosilver particle formation, it was shown that the particle size of the nanosilver products depends on the concentration of the reaction components and their stoichiometric ratio. It was also shown that the reaction system using AOT surfactant is capable of producing nanosilver particles with smallest nanoparticles ({phi}{sub av} {approx} 5 nm) and good particle-size distribution. The study on bactericidal activity of the nanosilver products indicated that the disinfecting solution with a nanosilver concentration of 3 ppm was able to inhibit all E.coli and Coliforms, TPC and fungi at 15 ppm, while Vibrio cholerae cells were inactivated completely with 0.5 ppm of nanosilver after 30 minutes exposition.

  14. Effect of influenza infection on the phagocytic and bactericidal activities of pulmonary macrophages

    International Nuclear Information System (INIS)

    The effect of mouse-adapted influenza A/PR/8/34 virus on pulmonary macrophage function was evaluated by using an in vitro system which allowed direct virus interaction with macrophages and then separate analysis of the steps required for bacterial clearance by macrophages. Infection of macrophages with this virus resulted in the appearance of a hemagglutinating activity on the macrophage surface; expression of this activity was inhibited by amantadine, 2-deoxyglucose, and cycloheximide and by pretreatment of the virus inoculum with with ultraviolet light and specific antiserum. After influenza infection, net ingestion of viable Staphylococcus aureus by macrophage monolayers was unaltered and there was no change in the fraction of the monolayer which ingested cocci over a wide range of bacterial inputs. Influenza-infected microphages also inactivated intracellular S. aureus at a rate indistinguishable from controls. Therefore, these in vitro studies do not support the hypothesis that the defect in pulmonary antibacterial mechanisms associated with influenza infections results from a direct effect of virus infection on either the phagocytic or bactericidal activity of resistant pulmonary macarophages

  15. IPN hydrogel nanocomposites based on agarose and ZnO with antifouling and bactericidal properties.

    Science.gov (United States)

    Wang, Jingjing; Hu, Hongkai; Yang, Zhonglin; Wei, Jun; Li, Juan

    2016-04-01

    Nanocomposite hydrogels with interpenetrating polymer network (IPN) structure based on poly(ethylene glycol) methyl ether methacrylate modified ZnO (ZnO-PEGMA) and 4-azidobenzoic agarose (AG-N3) were prepared by a one-pot strategy under UV irradiation. The hydrogels exhibited a highly macroporous spongelike structure, and the pore size decreased with the increase of the ZnO-PEGMA content. Due to the entanglement and favorable interactions between the two crosslinked networks, the IPN hydrogels exhibited excellent mechanical strength and light transmittance. The maximum compressive and tensile strengths of the IPN hydrogels reached 24.8 and 1.98MPa respectively. The transparent IPN hydrogels transmitted more than 85% of visible light at all wavelengths (400-800nm). The IPN hydrogels exhibited anti-adhesive property towards Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), and the bactericidal activity increased with the ZnO-PEGMA content. The incorporation of ZnO-PEGMA did not reduce the biocompatibility of the IPN hydrogels and all the IPN nanocomposites showed negligible cytotoxicity. The present study not only provided a facile method for preparing hydrogel nanocomposites with IPN structure but also developed a new hydrogel material which might be an excellent candidate for wound dressings. PMID:26838864

  16. Bactericidal paper trays doped with silver nanoparticles for egg storing applications

    Indian Academy of Sciences (India)

    KALIYAPERUMAL VISWANATHAN; M LATHA MALA PRIYADHARSHINI; KARUPPASAMY NIRMALA; MUTHUSAMY RAMAN; GOPAL DHINAKAR RAJ

    2016-06-01

    In this study, a cost-effective way to deposit the silver nanoparticles (AgNPs) on paper egg trays was developed, which proved suitable for prolonged storage of table eggs for house-hold use without deterioration of egg quality. Silver nanoparticles were synthesized based on chemical reduction approach and mixed with gelatin–chitosan mixer used as a colloidal stabilizer as well as fixing agent. AgNPs-doped paper egg trays were characterized by TEM, SEM, FTIR, EDX and XRD. AgNPs containing egg trays were tested for its bactericidal effect against commonly found bacteria on egg shells, E. coli, S. aureus, Streptococcus spp and Salmonella spp. Storing of eggs in the AgNPs-deposited paper egg trays improved the shelf-life of the eggs by more than 14 days compared to controls (eggs stored in conventional trays). In conclusion, the developed paper trays possessed strong antimicrobial activity and it could be an effective storage material for eggs.

  17. Bactericidal evaluation of N-halamine-functionalized silica nanoparticles based on barbituric acid.

    Science.gov (United States)

    Dong, Alideertu; Xue, Min; Lan, Shi; Wang, Qin; Zhao, Yue; Wang, Ying; Zhang, Yanling; Gao, Ge; Liu, Fengqi; Harnoode, Chokto

    2014-01-01

    Novel N-halamine-functionalized silica nanoparticles (NHFS NPs) were facilely fabricated from the 5-allylbarbituric acid (ABBA) by a seeded copolymerization using colloidal silica nanoparticles as support and ABBA-based N-halamine copolymers as shell. The NHFS NPs with spherical morphology and legible core-shell structure have the average diameter of 538.5 nm and the average shell thickness of 19.8 nm. The NHFS NPs possessed improved antimicrobial activity against both Gram-positive and Gram-negative bacteria compared with their bulk powder counterparts. The structural effect of N-halamine on bactericidal activity was clarified through the comparison between barbituric acid-based NHFS NPs and hydantoin-structural NHFS NPs. Effects of colloidal silica support and comonomer methyl methacrylate on particles morphology and the corresponding antimicrobial activity were comparatively investigated as well. Antibacterial tests revealed that N-halamine nanomaterials originated from barbituric acid derivative displayed powerful antibacterial performance and long-term stability. PMID:24144511

  18. Bactericidal performance of visible-light responsive titania photocatalyst with silver nanostructures.

    Directory of Open Access Journals (Sweden)

    Ming-Show Wong

    Full Text Available BACKGROUND: Titania dioxide (TiO(2 photocatalyst is primarily induced by ultraviolet light irradiation. Visible-light responsive anion-doped TiO(2 photocatalysts contain higher quantum efficiency under sunlight and can be used safely in indoor settings without exposing to biohazardous ultraviolet light. The antibacterial efficiency, however, remains to be further improved. METHODOLOGY/PRINCIPAL FINDINGS: Using thermal reduction method, here we synthesized silver-nanostructures coated TiO(2 thin films that contain a high visible-light responsive antibacterial property. Among our tested titania substrates including TiO(2, carbon-doped TiO(2 [TiO(2 (C] and nitrogen-doped TiO(2 [TiO(2 (N], TiO(2 (N showed the best performance after silver coating. The synergistic antibacterial effect results approximately 5 log reductions of surviving bacteria of Escherichia coli, Streptococcus pyogenes, Staphylococcus aureus and Acinetobacter baumannii. Scanning electron microscope analysis indicated that crystalline silver formed unique wire-like nanostructures on TiO(2 (N substrates, while formed relatively straight and thicker rod-shaped precipitates on the other two titania materials. CONCLUSION/SIGNIFICANCE: Our results suggested that proper forms of silver on various titania materials could further influence the bactericidal property.

  19. Biosynthesis and recovery of rod-shaped tellurium nanoparticles and their bactericidal activities

    Energy Technology Data Exchange (ETDEWEB)

    Zare, Bijan; Faramarzi, Mohammad Ali; Sepehrizadeh, Zargham [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. Box 14155-6451 Tehran (Iran, Islamic Republic of); Shakibaie, Mojtaba [Department of Pharmacognosy and Biotechnology, School of Pharmacy, Pharmaceutics Research Center, Kerman University of Medical Sciences, P.O. Box 76175-493 Kerman (Iran, Islamic Republic of); Rezaie, Sassan [Department of Medical Biotechnology, School of Advanced Medical Technologies, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shahverdi, Ahmad Reza, E-mail: shahverd@sina.tums.ac.ir [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. Box 14155-6451 Tehran (Iran, Islamic Republic of)

    2012-11-15

    Highlights: ► Biosynthesis of rod shape tellurium nanoparticles with a hexagonal crystal structure. ► Extraction procedure for isolation of tellurium nanoparticles from Bacillus sp. BZ. ► Extracted tellurium nanoparticles have good bactericidal activity against some bacteria. -- Abstract: In this study, a tellurium-transforming Bacillus sp. BZ was isolated from the Caspian Sea in northern Iran. The isolate was identified by various tests and 16S rDNA analysis, and then used to prepare elemental tellurium nanoparticles. The isolate was subsequently used for the intracellular biosynthesis of elemental tellurium nanoparticles. The biogenic nanoparticles were released by liquid nitrogen and purified by an n-octyl alcohol water extraction system. The shape, size, and composition of the extracted nanoparticles were characterized. The transmission electron micrograph showed rod-shaped nanoparticles with dimensions of about 20 nm × 180 nm. The energy dispersive X-ray and X-ray diffraction spectra respectively demonstrated that the extracted nanoparticles consisted of only tellurium and have a hexagonal crystal structure. This is the first study to demonstrate a biological method for synthesizing rod-shaped elemental tellurium by a Bacillus sp., its extraction and its antibacterial activity against different clinical isolates.

  20. Polyurethane foams doped with stable silver nanoparticles as bactericidal and catalytic materials for the effective treatment of water

    OpenAIRE

    Domènech Garcia, Berta; Ziegler Benítez, Kharla; Vigués Frantzen, Núria; Olszewski, Wojciech; Marini, Carlo; Mas Gordi, Jordi; Muñoz Tapia, Maria; Muraviev, Dmitri N; Macanás de Benito, Jorge

    2016-01-01

    The development of reusable dual-purpose nanocomposite foams for catalytic and bactericidal water treatment is reported. Small non-aggregated silver nanoparticles were made using Intermatrix Synthesis inside a polyurethane foam, which was chosen as a suitable polymeric matrix due to its high chemical and mechanical stability and industrial applicability. The antibacterial activity of the obtained nanocomposites was evaluated against suspensions of Gram-negative bacteria (E. coli), showing ide...

  1. The Combination of Doripenem and Colistin Is Bactericidal and Synergistic against Colistin-Resistant, Carbapenemase-Producing Klebsiella pneumoniae

    OpenAIRE

    Jernigan, Meredith G.; Press, Ellen G.; Nguyen, M. Hong; Clancy, Cornelius J.; Shields, Ryan K.

    2012-01-01

    We tested two-drug combinations of doripenem, colistin, gentamicin, and doxycycline against 12 carbapenemase-producing Klebsiella pneumoniae (KPC) isolates by time-kill. The combination of doripenem and colistin reduced the starting inocula by 2 logs for each isolate (range, 2.02 to 6.01 log10) and was bactericidal and synergistic against 75 and 50%, respectively. Among colistin- and pan-drug-resistant isolates, synergy was identified in 60 and 67%, respectively. All other combinations were i...

  2. A Bayesian Nonlinear Mixed-Effects Regression Model for the Characterization of Early Bactericidal Activity of Tuberculosis Drugs

    OpenAIRE

    Burger, Divan Aristo; Schall, Robert

    2014-01-01

    Trials of the early bactericidal activity (EBA) of tuberculosis (TB) treatments assess the decline, during the first few days to weeks of treatment, in colony forming unit (CFU) count of Mycobacterium tuberculosis in the sputum of patients with smear-microscopy-positive pulmonary TB. Profiles over time of CFU data have conventionally been modeled using linear, bilinear, or bi-exponential regression. We propose a new biphasic nonlinear regression model for CFU data that comprises linear and bi...

  3. Studies on characteristics of nanostructure of N-TiO2 thin films and photo-bactericidal action

    Institute of Scientific and Technical Information of China (English)

    XU Ming-fang; LIN Shan; CHEN Xin-man; PENG Yan-zhi

    2006-01-01

    Pseudomonas aeruginosa strain (AS 1.50) and Bacillus subtilis strain ( AS 1.49 ) from Ming lake were decomposed by photocatalytic nanostructure N-TiO2 thin films in a photo-reactor under UV irradiation. The different thickness nanostructure N-TiO2 thin films coated on mesh grid were prepared by sol-gel method and immobilized at 500 ℃ (films A) or 350 ℃ (films B)for 1 h in a muffle furnace. The results showed that N-TiO2 thin film B (8.18 nm thickness, 2.760 nm height and 25.15 nm diameter) has more uniform granular nanostructure and thinner flat texture than N-TiO2 thin film A (12.17 nm thickness, 3.578 nm height and 27.50 nm diameter). The bactericidal action of N-TiO2 thin film A and film B for Pseudomonas aeruginosa strain (AS1.50) and Bacillus subtilis varniger strain (AS1.439) were investigated in this work. More than 95% of photocatalytic bactericidal efficiency for Pseudomonas aeruginosa strain (AS1.50) and 75% for Bacillus subtilis strain (AS1.439) were achieved by using N-TiO2 thin films-B for 70~80 min of irradiation during the photo-bactericidal experimental process. The results indicated that the photo-induced bactericidal efficiency of N-TiO2 thin films probably depended on the characteristics of the films.

  4. Comparison of Methods for Evaluation of the Bactericidal Activity of Copper-Sputtered Surfaces against Methicillin-Resistant Staphylococcus aureus

    OpenAIRE

    Rio, Laura; Kusiak-Nejman, Ewelina; Kiwi, John; Betrisey, Bertrand; Pulgarin, Cesar; Trampuz, Andrej; Bizzini, Alain

    2012-01-01

    Bacteria can survive on hospital textiles and surfaces, from which they can be disseminated, representing a source of health care-associated infections (HCAIs). Surfaces containing copper (Cu), which is known for its bactericidal properties, could be an efficient way to lower the burden of potential pathogens. The antimicrobial activity of Cu-sputtered polyester surfaces, obtained by direct-current magnetron sputtering (DCMS), against methicillin-resistant Staphylococcus aureus (MRSA) was tes...

  5. Cell-wall determinants of the bactericidal action of group IIA phospholipase A2 against Gram-positive bacteria

    OpenAIRE

    Foreman-Wykert, Amy K.; Weinrauch, Yvette; Elsbach, Peter; Weiss, Jerrold

    1999-01-01

    We have shown previously that a group IIA phospholipase A2 (PLA2) is responsible for the potent bactericidal activity of inflammatory fluids against many Gram-positive bacteria. To exert its antibacterial activity, this PLA2 must first bind and traverse the bacterial cell wall to produce the extensive degradation of membrane phospholipids (PL) required for bacterial killing. In this study, we have examined the properties of the cell-wall that may determine the potency of group IIA PLA2 action...

  6. Bactericidal activity under UV and visible light of cotton fabrics coated with anthraquinone-sensitized TiO2

    KAUST Repository

    Rahal, Raed

    2013-06-01

    This study describes a method derived from ISO/TC 206/SC specifications to assess the bactericidal activity against a bacterial strain, Pseudomonas fluorescens, of various photocatalytic fabrics, under UVA and filtered visible light. The experimental method allowed the accurate quantification of bacteria survival on photoactive surfaces and films under UVA and UV-free visible irradiation. Cotton fabrics coated with TiO2, anthraquinone or anthraquinone-sensitized TiO2 display a significant bactericidal efficiency. TiO2-coated fabrics are very efficient against P. fluorescens after 4 h UVA irradiation (bacteria survival below the detection limit). Under UVA-free visible light, anthraquinone-sensitized TiO2 coated fabrics induced a significant bactericidal activity after 2 h irradiation, while anthraquinone alone-coated fabrics were not as efficient and TiO2 coated fabrics were almost inefficient. These results show that although exhibiting a weak n-π* band in the 350-420 nm range, anthraquinone is a good candidate as an efficient visible light photosensitizer. A synergy effect between anthraquinone and TiO2 was demonstrated. A possible reaction mechanism, involving a synergy effect for singlet oxygen formation with anthraquinone-sensitized TiO2 is proposed to account for these results. © 2012 Elsevier B.V. All rights reserved.

  7. Anti-bactericidal properties of stingray Dasyatis pastinaca groups V, IIA, and IB phospholipases A2: a comparative study.

    Science.gov (United States)

    Bacha, Abir Ben

    2014-10-01

    Group IIA secreted phospholipase A2 (group IIA sPLA2) is known to display potent Gram-positive bactericidal activity in vitro and in vivo. We have analyzed the bactericidal activity of the full set of native stingray and dromedary groups V, IIA, and IB sPLA2s on several Gram-positive and Gram-negative strains. The rank order potency among both marine and mammal sPLA2s against Gram-positive bacteria is group IIA > V > IB, whereas Gram-negative bacteria exhibited a much higher resistance. There is a synergic action of the sPLA2 with lysozyme when added to the bacteria culture prior to sPLA2.The bactericidal efficiency of groups V and IIA sPLA2s was shown to be dependent upon the presence of calcium ions and to a less extent Mg(2+) ions and then a correlation could be made to its hydrolytic activity of membrane phospholipids. Importantly, we showed that stingray and dromedary groups V, IIA, and IB sPLA2s present no cytotoxicity after their incubation with MDA-MB-231cells. stingray groups V and IIA sPLA2s, like mammal ones, may be considered as future therapeutic agents against bacterial infections. PMID:25119545

  8. In Vitro Bactericidal Effects of 625, 525, and 425 nm Wavelength (Red, Green, and Blue) Light-Emitting Diode Irradiation

    OpenAIRE

    Kim, Sangwoo; Kim, Jisun; Lim, Wonbong; Jeon, Sangmi; Kim, OkSu; Koh, Jeong-Tae; Kim, Chang-Su; Choi, Hongran; Kim, Okjoon

    2013-01-01

    Objective: The purpose of this study was to evaluate the relationship of 625, 525, and 425 nm wavelengths, providing average power output and effects on three common pathogenic bacteria. Background data: Ultraviolet (UV) light kills bacteria, but the bactericidal effects of UV may not be unique, as 425 nm produces a similar effect. The bactericidal effects of light-emitting diode (LED) wavelengths such as 625 and 525 nm have not been described. Before conducting clinical trials, the approp...

  9. Enhanced bactericidal potency of nanoliposomes by modification of the fusion activity between liposomes and bacterium

    Directory of Open Access Journals (Sweden)

    Ma YF

    2013-06-01

    amount of negative charges in fluid liposomes reduces fluid liposomes-bacteria fusion when tested without calcium cations due to electric repulsion, but addition of calcium cations brings the fusion level of fluid liposomes to similar or higher levels. Among the negative phospholipids examined, DMPA gave the highest degree of fusion, DMPS and DMPG had intermediate fusion levels, and PI resulted in the lowest degree of fusion. Furthermore, the fluid liposomal encapsulated tobramycin was prepared, and the bactericidal effect occurred more quickly when bacteria were cultured with liposomal encapsulated tobramycin. Conclusion: The bactericidal potency of fluid liposomes is dramatically enhanced with respect to fusion ability when the fusogenic lipid, DOPE, is included. Regardless of changes in liposome composition, fluid liposomes-bacterium fusion is universally enhanced by calcium ions. The information obtained in this study will increase our understanding of fluid liposomal action mechanisms, and help in optimizing the new generation of fluid liposomal formulations for the treatment of pulmonary bacterial infections. Keywords: liposomes, fusion, bacteria, Pseudomonas aeruginosa, lipid composition

  10. Expression of bactericidal/permeability-increasing protein requires C/EBP epsilon.

    Science.gov (United States)

    Tanaka, Miyuki; Gombart, Adrian F; Koeffler, H Phillip; Shiohara, Masaaki

    2007-05-01

    Bactericidal/permeability-increasing protein (BPI) is a 55-kd cationic protein found mainly in neutrophil primary granules. BPI shows cytotoxicity against Gram-negative bacteria. In this study, we studied the role of a myeloid-specific transcription factor, CCAAT/enhancer binding protein epsilon (C/EBP epsilon), in the regulation of BPI gene expression. A patient with neutrophil-specific granule deficiency with a homozygous inactivating mutation in the CEBP epsilon gene showed severely impaired expression of both BPI messenger RNA (mRNA) and BPI protein. Both U937 and NB4 cells treated with 10-7 M all-trans retinoic acid (ATRA) for 6 days displayed increased levels of BPI protein and accompanying up-regulated C/EBP epsilon expression. Chromatin-immunoprecipitation analysis and electrophoretic mobility shift assays revealed binding of the C/EBP epsilon protein to the C/EBP-binding site in the BPI gene promoter. U937 cells stably transfected with a zinc-inducible C/EBP epsilon expression vector showed a 30-fold increase in BPI mRNA levels compared with cells transfected with control empty vector after culturing for 48 hours with 100 microM ZnSO4. BPI mRNA expression was severely reduced in the bone marrow of C/EBP epsilon-deficient mice compared with wild-type mice. Expression of BPI in human cord blood cells was increased by incubation with 10-7 MATRA for 48 hours. These results demonstrate the requirement for C/EBP epsilon in mediating BPI gene expression in myeloid cells in vitro and in vivo. PMID:17483073

  11. Synergistic bactericidal effect by combined exposure to Ag nanoparticles and UVA

    International Nuclear Information System (INIS)

    Broad and strong antimicrobial properties of silver (Ag) have been used for biomedical applications, water treatment, etc. In this study, a synergistic antibacterial effect between Ag nanoparticles (AgNPs) and ultraviolet (UV) light was examined. AgNPs ( 1 μm) with UVA and AgNPs with UVB (280–325 nm) did not. As significant bactericidal activity was also exhibited by hydrogen peroxide-treated AgNPs, the surface oxidation of AgNPs caused by UVA irradiation was considered to contribute to the enhanced antibacterial effect. Although no difference in NP-incorporation rates was observed with or without the surface oxidation of AgNPs, a particle size of less than 0.1 μm was a factor for AgNPs uptake and an essential requirement for the antimicrobial function of Ag particles. Incorporated AgNPs oxidized by UVA irradiation released larger amounts of Ag ion inside cells than reduced AgNPs, which reacted with intercellular molecules having –SH groups such as glutathione. The synergistic use of AgNPs and UVA could become a powerful tool with broad antimicrobial applications. Highlights: • Combined treatment with AgNPs and UV achieved a remarkable antibacterial effect in E. coli. • For the antibacterial effect, it is necessary to satisfy the following requirements: • 1) Translocation of nano-sized Ag particles inside E. coli. • 2) Oxidation of AgNPs by UVA, and extensive and persistent release of Ag+ inside E. coli. • Ag+ released inside cells reacted with intercellular molecules having –SH groups such as GSH

  12. Radioiodinated DPA-713 imaging correlates with bactericidal activity of tuberculosis treatments in mice.

    Science.gov (United States)

    Ordonez, Alvaro A; Pokkali, Supriya; DeMarco, Vincent P; Klunk, Mariah; Mease, Ronnie C; Foss, Catherine A; Pomper, Martin G; Jain, Sanjay K

    2015-01-01

    Current tools for monitoring response to tuberculosis treatments have several limitations. Noninvasive biomarkers could accelerate tuberculosis drug development and clinical studies, but to date little progress has been made in developing new imaging technologies for this application. In this study, we developed pulmonary single-photon emission computed tomography (SPECT) using radioiodinated DPA-713 to serially monitor the activity of tuberculosis treatments in live mice, which develop necrotic granulomas and cavitary lesions. C3HeB/FeJ mice were aerosol infected with Mycobacterium tuberculosis and administered either a standard or a highly active bedaquiline-containing drug regimen. Serial (125)I-DPA-713 SPECT imaging was compared with (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) and standard microbiology. Ex vivo studies were performed to characterize and correlate DPA-713 imaging with cellular and cytokine responses. Pulmonary (125)I-DPA-713 SPECT, but not (18)F-FDG PET, was able to correctly identify the bactericidal activities of the two tuberculosis treatments as early as 4 weeks after the start of treatment (P < 0.03). DPA-713 readily penetrated the fibrotic rims of necrotic and cavitary lesions. A time-dependent decrease in both tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) levels was observed with treatments, with (125)I-DPA-713 SPECT correlating best with tissue TNF-α levels (ρ = 0.94; P < 0.01). (124)I-DPA-713 was also evaluated as a PET probe and demonstrated a 4.0-fold-higher signal intensity in the infected tuberculous lesions than uninfected controls (P = 0.03). These studies provide proof of concept for application of a novel noninvasive imaging biomarker to monitor tuberculosis treatments, with the potential for application for humans. PMID:25403669

  13. The bactericidal effect of dendritic copper microparticles, contained in an alginate matrix, on Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Simon F Thomas

    Full Text Available Although the bactericidal effect of copper has been known for centuries, there is a current resurgence of interest in the use of this element as an antimicrobial agent. During this study the use of dendritic copper microparticles embedded in an alginate matrix as a rapid method for the deactivation of Escherichia coli ATCC 11775 was investigated. The copper/alginate produced a decrease in the minimum inhibitory concentration from free copper powder dispersed in the media from 0.25 to 0.065 mg/ml. Beads loaded with 4% Cu deactivated 99.97% of bacteria after 90 minutes, compared to a 44.2% reduction in viability in the equivalent free copper powder treatment. There was no observed loss in the efficacy of this method with increasing bacterial loading up to 10(6 cells/ml, however only 88.2% of E. coli were deactivated after 90 minutes at a loading of 10(8 cells/ml. The efficacy of this method was highly dependent on the oxygen content of the media, with a 4.01% increase in viable bacteria observed under anoxic conditions compared to a >99% reduction in bacterial viability in oxygen tensions above 50% of saturation. Scanning electron micrographs (SEM of the beads indicated that the dendritic copper particles sit as discrete clusters within a layered alginate matrix, and that the external surface of the beads has a scale-like appearance with dendritic copper particles extruding. E. coli cells visualised using SEM indicated a loss of cellular integrity upon Cu bead treatment with obvious visible blebbing. This study indicates the use of microscale dendritic particles of Cu embedded in an alginate matrix to effectively deactivate E. coli cells and opens the possibility of their application within effective water treatment processes, especially in high particulate waste streams where conventional methods, such as UV treatment or chlorination, are ineffective or inappropriate.

  14. Hydrophilic, bactericidal nanoheater-enabled reverse osmosis membranes to improve fouling resistance.

    Science.gov (United States)

    Ray, Jessica R; Tadepalli, Sirimuvva; Nergiz, Saide Z; Liu, Keng-Ku; You, Le; Tang, Yinjie; Singamaneni, Srikanth; Jun, Young-Shin

    2015-06-01

    Polyamide (PA) semipermeable membranes typically used for reverse osmosis water treatment processes are prone to fouling, which reduces the amount and quality of water produced. By synergistically coupling the photothermal and bactericidal properties of graphene oxide (GO) nanosheets, gold nanostars (AuNS), and hydrophilic polyethylene glycol (PEG) on PA reverse osmosis membrane surfaces, we have dramatically improved fouling resistance of these membranes. Batch fouling experiments from three classes of fouling are presented: mineral scaling (CaCO3 and CaSO4), organic fouling (humic acid), and biofouling (Escherichia coli). Systematic analyses and a variety of complementary techniques were used to elucidate fouling resistance mechanisms from each layer of modification on the membrane surface. Both mineral scaling and organic fouling were significantly reduced in PA-GO-AuNS-PEG membranes compared to other membranes. The PA-GO-AuNS-PEG membrane was also effective in killing all near-surface bacteria compared to PA membranes. In the PA-GO-AuNS-PEG membrane, the GO nanosheets act as templates for in situ AuNS growth, which then facilitated localized heating upon irradiation by an 808 nm laser inactivating bacteria on the membrane surface. Furthermore, AuNS in the membrane assisted PEG in preventing mineral scaling on the membrane surface. In flow-through flux and foulant rejection tests, PA-GO-AuNS-PEG membranes performed better than PA membranes in the presence of CaSO4 and humic acid model foulants. Therefore, the newly suggested membrane surface modifications will not only reduce fouling from RO feeds, but can improve overall membrane performance. Our innovative membrane design reported in this study can significantly extend the lifetime and water treatment efficacy of reverse osmosis membranes to alleviate escalating global water shortage from rising energy demands. PMID:25941970

  15. The bactericidal agent triclosan modulates thyroid hormone-associated gene expression and disrupts postembryonic anuran development

    International Nuclear Information System (INIS)

    We investigated whether exposure to environmentally relevant concentrations of the bactericidal agent, triclosan, induces changes in the thyroid hormone-mediated process of metamorphosis of the North American bullfrog, Rana catesbeiana and alters the expression profile of thyroid hormone receptor (TR) α and β, basic transcription element binding protein (BTEB) and proliferating nuclear cell antigen (PCNA) gene transcripts. Premetamorphic tadpoles were immersed in environmentally relevant concentrations of triclosan and injected with 1 x 10-11 mol/g body weight 3,5,3'-triiodothyronine (T3) or vehicle control. Morphometric measurements and steady-state mRNA levels obtained by quantitative polymerase chain reaction were determined. mRNA abundance was also examined in Xenopus laevis XTC-2 cells treated with triclosan and/or 10 nM T3. Tadpoles pretreated with triclosan concentrations as low as 0.15 ± 0.03 μg/L for 4 days showed increased hindlimb development and a decrease in total body weight following T3 administration. Triclosan exposure also resulted in decreased T3-mediated TRβ mRNA expression in the tadpole tail fin and increased levels of PCNA transcript in the brain within 48 h of T3 treatment whereas TRα and BTEB were unaffected. Triclosan alone altered thyroid hormone receptor α transcript levels in the brain of premetamorphic tadpoles and induced a transient weight loss. In XTC-2 cells, exposure to T3 plus nominal concentrations of triclosan as low as 0.03 μg/L for 24 h resulted in altered thyroid hormone receptor mRNA expression. Exposure to low levels of triclosan disrupts thyroid hormone-associated gene expression and can alter the rate of thyroid hormone-mediated postembryonic anuran development

  16. The bactericidal agent triclosan modulates thyroid hormone-associated gene expression and disrupts postembryonic anuran development

    Energy Technology Data Exchange (ETDEWEB)

    Veldhoen, Nik [Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Skirrow, Rachel C. [Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2 (Canada); Osachoff, Heather [Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2 (Canada); Wigmore, Heidi [Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2 (Canada); Clapson, David J. [Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Gunderson, Mark P. [Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Van Aggelen, Graham [Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2 (Canada); Helbing, Caren C. [Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada)]. E-mail: chelbing@uvic.ca

    2006-12-01

    We investigated whether exposure to environmentally relevant concentrations of the bactericidal agent, triclosan, induces changes in the thyroid hormone-mediated process of metamorphosis of the North American bullfrog, Rana catesbeiana and alters the expression profile of thyroid hormone receptor (TR) {alpha} and {beta}, basic transcription element binding protein (BTEB) and proliferating nuclear cell antigen (PCNA) gene transcripts. Premetamorphic tadpoles were immersed in environmentally relevant concentrations of triclosan and injected with 1 x 10{sup -11} mol/g body weight 3,5,3'-triiodothyronine (T{sub 3}) or vehicle control. Morphometric measurements and steady-state mRNA levels obtained by quantitative polymerase chain reaction were determined. mRNA abundance was also examined in Xenopus laevis XTC-2 cells treated with triclosan and/or 10 nM T{sub 3}. Tadpoles pretreated with triclosan concentrations as low as 0.15 {+-} 0.03 {mu}g/L for 4 days showed increased hindlimb development and a decrease in total body weight following T{sub 3} administration. Triclosan exposure also resulted in decreased T{sub 3}-mediated TR{beta} mRNA expression in the tadpole tail fin and increased levels of PCNA transcript in the brain within 48 h of T{sub 3} treatment whereas TR{alpha} and BTEB were unaffected. Triclosan alone altered thyroid hormone receptor {alpha} transcript levels in the brain of premetamorphic tadpoles and induced a transient weight loss. In XTC-2 cells, exposure to T{sub 3} plus nominal concentrations of triclosan as low as 0.03 {mu}g/L for 24 h resulted in altered thyroid hormone receptor mRNA expression. Exposure to low levels of triclosan disrupts thyroid hormone-associated gene expression and can alter the rate of thyroid hormone-mediated postembryonic anuran development.

  17. Synergistic bactericidal effect by combined exposure to Ag nanoparticles and UVA

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xiaoxu; Toyooka, Tatsushi; Ibuki, Yuko, E-mail: ibuki@u-shizuoka-ken.ac.jp

    2013-08-01

    Broad and strong antimicrobial properties of silver (Ag) have been used for biomedical applications, water treatment, etc. In this study, a synergistic antibacterial effect between Ag nanoparticles (AgNPs) and ultraviolet (UV) light was examined. AgNPs (< 0.1 μm) with subsequent exposure to UVA (320–400 nm) showed pronounced toxicity in Escherichia coli, but micro-sized Ag particles (> 1 μm) with UVA and AgNPs with UVB (280–325 nm) did not. As significant bactericidal activity was also exhibited by hydrogen peroxide-treated AgNPs, the surface oxidation of AgNPs caused by UVA irradiation was considered to contribute to the enhanced antibacterial effect. Although no difference in NP-incorporation rates was observed with or without the surface oxidation of AgNPs, a particle size of less than 0.1 μm was a factor for AgNPs uptake and an essential requirement for the antimicrobial function of Ag particles. Incorporated AgNPs oxidized by UVA irradiation released larger amounts of Ag ion inside cells than reduced AgNPs, which reacted with intercellular molecules having –SH groups such as glutathione. The synergistic use of AgNPs and UVA could become a powerful tool with broad antimicrobial applications. Highlights: • Combined treatment with AgNPs and UV achieved a remarkable antibacterial effect in E. coli. • For the antibacterial effect, it is necessary to satisfy the following requirements: • 1) Translocation of nano-sized Ag particles inside E. coli. • 2) Oxidation of AgNPs by UVA, and extensive and persistent release of Ag{sup +} inside E. coli. • Ag{sup +} released inside cells reacted with intercellular molecules having –SH groups such as GSH.

  18. Spectrophotometric Screening of Potent Bactericidal Property of Thevetia Peruviana Schum. Leaf and Fruit Rind Extracts on Clinical and Plant Pathogens

    Directory of Open Access Journals (Sweden)

    Nazneen Rahman

    2014-12-01

    Full Text Available The development of multi drug resistance in human and plant pathogens, reconsidering the traditional medicines as antibacterial source and presence of promising phytochemicals in leaf and fruit rind of T. peruviana (S (Nazneen et al., 2014 prompted the authors to take up the antibacterial evaluation of different extracts. Antibacterial activity, minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC of various extracts of T. peruviana (S were measured using methods of National Committee for Clinical Laboratory Standards (NCCLS. The minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC spectrophotometric determination of active extracts has found that the MICs of all the active extracts lies between the range of 250 μg to 1250 μg and bactericidal concentration in a range of 500 to 1250 μg. The percentage of inhibition was analysed, where in among all the extracts tested against B. subtilis and E. coli, fruit upper liquid (FUL exhibited highest inhibition percentage of 33.75% and 30.31 % at 500 μg/ml respectively. Similarly, fruit hexane (FH extract has the highest inhibition of 15.60% against B. cereus at 750 μg/ml. The Xanthomonas sp. was susceptible to leaf chloroform (LC with 32.29% of inhibition at 1000 μg/ ml. The activity index and total antimicrobial activity indicates the antibacterial action of extracts. The present investigations have revealed that among the extracts, the fruit rind extracts have most prominent inhibition abilities against tested bacteria, which are validating the use of this plant in traditional system of medicine and this is the first report of exploration of above extracts for their antibacterial activities against B. subtilis, B. cereus, E. coli and Xanthomonas sp.

  19. Synthesis of bactericide Cyprodinil%杀菌剂嘧菌环胺的合成

    Institute of Scientific and Technical Information of China (English)

    瞿佳; 蔡鹏; 来虎钦; 李风月; 苗丽

    2012-01-01

    以环丙甲酮、乙酸乙酯、苯基胍碳酸盐为原料,经缩合、环合两步反应得到杀菌剂嘧菌环胺.考察了各步反应的溶剂选择、反应温度、反应时间、原料配比等因素对反应收率的影响.结果表明:缩合反应的较佳条件为:异丙醚作溶剂,n(环丙甲酮)∶n(金属钠)∶n(乙酸乙酯)=1∶1.3∶1.5,反应温度65℃,反应时间3h;环合反应的较佳条件为:甲苯作溶剂,n(1-环丙基-1,3丁二酮)∶n(苯基胍碳酸盐)=1∶0.7,反应温度110℃,反应时间3h.反应总收率达到76.3%,含量94.5%.产品及其中间体结构经1 H NMR和IR确证.%Using cyclopropyl methyl ketone? Ethyl acetate and phenylguanidine carbonate salt as raw materials, the bactericide Cyprodinil was prepared through the successive reactions of condensation and cyclization. The influences of solvent, temperature, time and molar ratio of materials were investigated. The optimum synthetic conditions were as follows: The condensation reaction solvent was isopropyl ether, n(cyclopropyl methyl ketone) : n(sodium) : n (ethyl acetate) = 1 : 1. 3 : 1. 5, reaction temperature was 65 ℃, reaction time was 3 h. The cyclization reaction solvent reaction was methylbenzene, n(l-cyclopropyl-l, 3-butanedione) '? N (phenylguanidine carbonate salt) = 1 : 0. 7, reaction temperature was 110 ℃ , reaction time was 3 h. The overall yield of Cyprodinil was 72. 4% with the purity of 96. 1%. The structures of the product and the intermediate were characterized by 1H NMR and IR.

  20. [Detection of bactericidal antibody in the breast milk of a mother infected with enterohemorrhagic Escherichia coli O157:H7].

    Science.gov (United States)

    Adachi, E; Tanaka, H; Toyoda, N; Takeda, T

    1999-05-01

    A 21 years-old pregnant woman developed diarrhea, fresh bloody stools and abdominal pain on April 6th 1997 at 32 weeks of gestation, and was admitted to the hospital on April 11th. The stool culture on admission was positive for enterohemorrhagic Escherichia coli (EHEC) O157:H7 (Stx1 and 2). Clinical laboratory data during admission showed only slight elevation of beta-microglobulin and N-acetyl glucosaminidase in the urine, and no neurological or hemolytic symptoms were seen. After the antibiotic and lactobacillus administration, all her symptoms were relieved and no abnormal findings in pregnancy were observed. She delivered a baby girl normally on May 30th. Serum (between 41 and 120 days from the onset) and milk (between 4 and 64 days post partum) samples from the mother, and serum (64 days of age) from a baby and cord blood were obtained to monitor the immune status against EHEC O157:H7 and against Shiga toxins (Stx). Anti-E. coli O157 LPS antibodies (IgA, G and M) were assayed by the ELISA method. Neutralizing anti-Stx antibodies were measured by using ACHN cell cytotoxicity assay. In the colostrum and mature milk, high levels of IgA and IgM, and no IgG antibodies against EHEC O157 LPS were detected. In one of the control colostrum samples obtained from 4 healthy mothers IgA antibody against EHEC O157 LPS was detected. To assess the potency of protection against EHEC O157:H7 by the breast milk, we monitored it by the bactericidal activity for the organism under complement-coincubation experiment, and by the neutralization test for the Stx cytotoxicity. As a result, breast milk samples (both colostrum and mature milk) from a patient were demonstrated to kill the organisms. One of 4 healthy milk samples, showed bactericidal activity though it was negative in O157-LPS antibody. This bactericidal activity seen in one healthy colostrum is possibly due to a nonspecific reaction caused by non-O157 E. coli infection. From these observations, it was suggested that the

  1. Bactericidal activity does not predict sterilizing activity: the case of rifapentine in the murine model of Mycobacterium ulcerans disease.

    Directory of Open Access Journals (Sweden)

    Deepak V Almeida

    Full Text Available BACKGROUND: Since 2004, treatment of Mycobacterium ulcerans disease, or Buruli ulcer, has shifted from surgery to daily treatment with streptomycin (STR + rifampin (RIF for 8 weeks. For shortening treatment duration, we tested the potential of daily rifapentine (RPT, a long-acting rifamycin derivative, as a substitute for RIF. METHODOLOGY/PRINCIPAL FINDINGS: BALB/c mice were infected with M. ulcerans in the right hind footpad and treated either daily (7/7 with STR+RIF or five days/week (5/7 with STR+RIF or STR+RPT for 4 weeks, beginning 28 days after infection when CFU counts were 4.88±0.51. The relative efficacy of the drug treatments was compared by footpad CFU counts during treatment and median time to footpad swelling after treatment cessation as measure of sterilizing activity. All drug treatments were bactericidal. After 1 week of treatment, the decline in CFU counts was significantly greater in treated mice but not different between the three treated groups. After 2 weeks of treatment, the decline in CFU was greater in mice treated with STR+RPT 5/7 than in mice treated with STR+RIF 7/7 and STR+RIF 5/7. After 3 and 4 weeks of treatment, CFU counts were nil in mice treated with STR+RPT and reduced by more than 3 and 4 logs in mice treated with STR+RIF 5/7 and STR+RIF 7/7, respectively. In sharp contrast to the bactericidal activity, the sterilizing activity was not different between all drug regimens although it was in proportion to the treatment duration. CONCLUSIONS/SIGNIFICANCE: The better bactericidal activity of daily STR+RIF and especially of STR+RPT did not translate into better prevention of relapse, possibly because relapse-freecure after treatment of Buruli ulcer is more related to the reversal of mycolactone-induced local immunodeficiency by drug treatment rather than to the bactericidal potency of drugs.

  2. Efficacy of pH elevation as a bactericidal strategy for treating ballast water of freight carriers

    Directory of Open Access Journals (Sweden)

    Clifford E. Starliper

    2015-05-01

    Full Text Available Treatment of ship ballast water with sodium hydroxide (NaOH is one method currently being developed to minimize the risk to introduce aquatic invasive species. The bactericidal capability of sodium hydroxide was determined for 148 bacterial strains from ballast water collected in 2009 and 2010 from the M/V Indiana Harbor, a bulk-freight carrier plying the Laurentian Great Lakes, USA. Primary culture of bacteria was done using brain heart infusion agar and a developmental medium. Strains were characterized based on PCR amplification and sequencing of a portion of the 16S rRNA gene. Sequence similarities (99+ % were determined by comparison with the National Center for Biotechnology Information (NCBI GenBank catalog. Flavobacterium spp. were the most prevalent bacteria characterized in 2009, comprising 51.1% (24/47 of the total, and Pseudomonas spp. (62/101; 61.4% and Brevundimonas spp. (22/101; 21.8% were the predominate bacteria recovered in 2010; together, comprising 83.2% (84/101 of the total. Testing was done in tryptic soy broth (TSB medium adjusted with 5 N NaOH. Growth of each strain was evaluated at pH 10.0, pH 11.0 and pH 12.0, and 4 h up to 72 h. The median cell count at 0 h for 148 cultures was 5.20 × 106 cfu/mL with a range 1.02 × 105–1.60 × 108 cfu/mL. The TSB adjusted to pH 10.0 and incubation for less than 24 h was bactericidal to 52 (35.1% strains. Growth in pH 11.0 TSB for less than 4 h was bactericidal to 131 (88.5% strains and pH 11.0 within 12 h was bactericidal to 141 (95.3%. One strain, Bacillus horikoshii, survived the harshest treatment, pH 12.0 for 72 h.

  3. Recombinant Bactericidal/Permeability-Increasing Protein (rBPI21) in Combination with Sulfadiazine Is Active against Toxoplasma gondii

    OpenAIRE

    Khan, Anis A.; Lambert, Lewis H.; Remington, Jack S.; Araujo, Fausto G.

    1999-01-01

    The activity of recombinant bactericidal/permeability-increasing protein (rBPI21), alone or in combination with sulfadiazine, on the intracellular replication of Toxoplasma gondii was assessed in vitro and in mice with acute toxoplasmosis. rBPI21 markedly inhibited the intracellular growth of T. gondii in human foreskin fibroblasts (HFFs). Following 72 h of exposure, the 50% inhibitory concentration of rBPI21 for T. gondii was 2.6 μg/ml, whereas only slight cytotoxicity for HFF cells was obse...

  4. Subsets of memory CD4+ T cell and bactericidal antibody response to Neisseria meningitidis serogroup C after immunization of HIV-infected children and adolescents.

    Directory of Open Access Journals (Sweden)

    Lucimar G Milagres

    Full Text Available Meningococcal disease is endemic in Brazil, with periodic outbreaks and case fatality rates reach as high as 18 to 20% of cases. Conjugate vaccines against meningococci are immunogenic in healthy children. However, we have previously shown a poor bactericidal antibody response to a Men C conjugate vaccine in Brazilian HIV-infected children and adolescents after a single vaccine administration. The goal of the present work was to investigate associations between bactericidal antibody response induced by MenC vaccine and the frequency and activation profile (expression of CD38, HLA-DR and CCR5 molecules of total CD4+ memory T cell sub-populations in HIV-1-infected children and adolescents. Responders to vaccination against MenC had a predominance (about 44% of CD4+ TINTERMEDIATE subset followed by TTRANSITIONAL memory subset (23 to 26%. Importantly, CD4+ TINT frequency was positively associated with bactericidal antibody response induced by vaccination. The positive correlation persisted despite the observation that the frequency TINT CD38+HLA-DR+ was higher in responders. In contrast, CD4+ TCENTRAL MEMORY (TCM subset negatively correlated with bactericidal antibodies. In conclusion, these data indicate that less differentiated CD+ T cells, like TCM may be constantly differentiating into intermediate and later differentiated CD4+ T cell subsets. These include CD4 TINT subset which showed a positive association with bactericidal antibodies.

  5. Bactericidal activity of moxifloxacin against multidrug-resistant Streptoccocus pneumoniae at clinically achievable serum and epithelial lining fluid concentrations compared with three other antimicrobials.

    Science.gov (United States)

    Cafini, Fabio; Alou, Luis; Sevillano, David; Valero, Eva; Prieto, José

    2004-10-01

    Time-kill studies compared the activities of moxifloxacin with those of levofloxacin, azithromycin and amoxicillin-clavulanate against 10 pneumococcal strains with various drug susceptibilities. Three Streptococcus pneumoniae strains were resistant to moxifloxacin: 6, 7 and 2 strains were resistant to levofloxacin, azithromycin and amoxicillin-clavulanate, respectively. Of these, 1 strain was resistant to all antimicrobial agents studied. Moxifloxacin and amoxicillin-clavulanate were bactericidal after 24h at serum Cmax levels against 9 and 8 strains, respectively, while levofloxacin and azithromycin were bactericidal against 3 and 2 strains, respectively. A higher activity was only observed for amoxicillin-clavulanate for logarithmic phase cultures at 1, 4 and 8h compared with stationary phase organisms. Amoxicillin-clavulanate and moxifloxacin were bactericidal at free serum levels (protein unbound) after 24h against 8 and 3 strains, respectively. Moxifloxacin was bactericidal at epithelial lining fluid levels against all strains at 24h, including one moxifloxacin, amoxicillin-clavulanate and azithromycin-resistant strain; lower levels of bactericidal activity was observed for levofloxacin, azithromycin and amoxicillin-clavulanate against 7, 2 and 4 strains, respectively. This demonstrated the importance of moxifloxacin tissue levels. PMID:15380257

  6. Preparation of cerium-doped TiO2 film on 304 stainless steel and its bactericidal effect in the presence of sulfate-reducing bacteria (SRB)

    International Nuclear Information System (INIS)

    Cerium-doped TiO2 film with bactericidal activity was prepared on 304 stainless steel by a sol-gel process. The doped cerium ions were identified to have retarding effect on the phase transition from amorphous TiO2 to anatase TiO2. This effect was interpreted as the distortion of crystal lattice, due to the introduction of cerium ions into the crystal structure of TiO2. The absorption band edge of cerium-doped TiO2 film has a red shift compared with that of pure TiO2 film in UV-vis spectra. The films covered with sulfate-reducing bacteria (SRB) medium were exposed to sunlight for 6 h and the bactericidal efficiency was evaluated with most probable number technique. It was found that the bactericidal efficiency of cerium-doped TiO2 film and pure TiO2 film were 95% and 85%, respectively.

  7. The effects of the bacterial interaction with visible-light responsive titania photocatalyst on the bactericidal performance

    Directory of Open Access Journals (Sweden)

    Cheng Chia-Liang

    2009-01-01

    Full Text Available Abstract Bactericidal activity of traditional titanium dioxide (TiO2 photocatalyst is effective only upon irradiation by ultraviolet light, which restricts the potential applications of TiO2 for use in our living environments. Recently carbon-containing TiO2 was found to be photoactive at visible-light illumination that affords the potential to overcome this problem; although, the bactericidal activity of these photocatalysts is relatively lower than conventional disinfectants. Evidenced from scanning electron microscopy and confocal Raman spectral mapping analysis, we found the interaction with bacteria was significantly enhanced in these anatase/rutile mixed-phase carbon-containing TiO2. Bacteria-killing experiments indicate that a significantly higher proportion of all tested pathogens including Staphylococcus aureus, Shigella flexneri and Acinetobacter baumannii, were eliminated by the new nanoparticle with higher bacterial interaction property. These findings suggest the created materials with high bacterial interaction ability might be a useful strategy to improve the antimicrobial activity of visible-light-activated TiO2.

  8. In vitro and in vivo bactericidal activity of Vitex negundo leaf extract against diverse multidrug resistant enteric bacterial pathogens

    Institute of Scientific and Technical Information of China (English)

    Muhammad Kamruzzaman; S.M. Nayeemul Bari; Shah M. Faruque

    2013-01-01

    Objective: To investigate in vitro and in vivo antibacterial potentials of Vitex negundo (V. negundo) leaf extracts against diverse enteric pathogens. Methods: Water and methanol extracts of V. negundo leaves were evaluated against enteric bacterial pathogens by using standard disc diffusion, viable bacterial cell count methods, determination of minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC). Results: Methanol extract of V. negundo leaves showed potent antibacterial activity (inhibition zone: 9.9-22.6 mm, MIC:200-3 200 μg/mL, MBC: 200-6 400 μg/mL) against all the pathogenic enteric bacteria (Vibriocholerae , Vibrio parahaemolyticus, Vibrio mimicus, Echerichia coli, Shigella spps., and Aeromonas spps) tested. Methanol extract of V. negundo leaves showed potent bactericidal activity both in vitro laboratory conditions (MBC, 200-400 μg/mL) and in the intestinal environment (Dose, 1-2 mg/mL) of infant mice against pathogenic Vibrio cholerae, the major causative agent of cholera. Furthermore, assays using the mice cholera model showed that V. negundo methanol extract can protect mice from Vibrio cholerae infection and significantly decrease the mortality rate (P<0.0001). Conclusions: For the first time we showed that methanol extract of V. negundo leaves exhibited strong vibriocidal activity both in vitro and in vivo conditions. Therefore, it will be useful to identify and isolate the active compounds of this extract that could be a good alternative of antibiotics to treat cholera.

  9. Photocatalytic Bactericidal Efficiency of Ag Doped TiO2/Fe3O4 on Fish Pathogens under Visible Light

    Directory of Open Access Journals (Sweden)

    Ekkachai Kanchanatip

    2014-01-01

    Full Text Available This research evaluates photocatalytic bactericidal efficiencies of Ag-TiO2/Fe3O4 in visible light using target pollutants that include Aeromonas hydrophila, Edwardsiella tarda, and Photobacterium damselae subsp. piscicida. The investigation started with Ag-TiO2/Fe3O4 synthesis and calcination followed by a series of product tests that include the examination of crystallite phase, light absorption, element composition morphology, and magnetic properties. The results of the experiment indicate that Ag and Fe3O4 significantly enhanced the light absorption capacity of TiO2 in the entire visible light range. The Ag-TiO2/Fe3O4 prepared in this study displays significantly enhanced visible light absorption and narrowed band gap energy. The magnetic property of Ag-TiO2/Fe3O4 made it easy for retrieval using a permanent magnet bar. The photocatalytic activity of Ag-TiO2/Fe3O4 remains above 85% after three application cycles, which indicates high and favorable efficiency in bactericidal evaluation. The experiments have proved that the Ag-TiO2/Fe3O4 magnetic photocatalyst is a promising photocatalyst for antibacterial application under visible light.

  10. In Vitro Bactericidal Activity of 4- and 5-Chloro-2-hydroxy-N-[1-oxo-1-(phenylaminoalkan-2-yl]benzamides against MRSA

    Directory of Open Access Journals (Sweden)

    Iveta Zadrazilova

    2015-01-01

    Full Text Available A series of nine substituted 2-hydroxy-N-[1-oxo-1-(phenylaminoalkan-2-yl]benzamides was assessed as prospective bactericidal agents against three clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA and S. aureus ATCC 29213 as the reference and quality control strain. The minimum bactericidal concentration was determined by subculturing aliquots from MIC determination onto substance-free agar plates. The bactericidal kinetics of compounds 5-chloro-2-hydroxy-N-[(2S-3-methyl-1-oxo-1-{[4-(trifluoromethylphenyl]amino}butan-2-yl]benzamide (1f, N-{(2S-1-[(4-bromophenylamino]-3-methyl-1-oxobutan-2-yl}-4-chloro-2-hydroxybenzamide (1g, and 4-chloro-N-{(2S-1-[(3,4-dichlorophenylamino]-3-methyl-1-oxobutan-2-yl}-2-hydroxybenzamide (1h was established by time-kill assay with a final concentration of the compound equal to 1x, 2x, and 4x MIC; aliquots were removed at 0, 4, 6, 8, and 24 h time points. The most potent bactericidal agent was compound 1f exhibiting remarkable rapid concentration-dependent bactericidal effect even at 2x MIC at 4, 6, and 8 h (with a reduction in bacterial count ranging from 3.08 to 3.75 log10 CFU/mL and at 4x MIC at 4, 6, 8, and 24 h (5.30 log10 CFU/mL reduction in bacterial count after incubation against MRSA 63718. Reliable bactericidal effect against other strains was maintained at 4x MIC at 24 h.

  11. Comparison of bactericidal efficiency of 7.5 MeV X-rays, gamma-rays, and 10 MeV e-beams

    Science.gov (United States)

    Song, Beom-Seok; Lee, Yunjong; Moon, Byeong-Geum; Go, Seon-Min; Park, Jong-Heum; Kim, Jae-Kyung; Jung, Koo; Kim, Dong-Ho; Ryu, Sang-Ryeol

    2016-08-01

    This study was performed to verify the feasibility of 7.5 MeV X-rays for food pasteurization through a comparison of the bactericidal efficiency with those of other sources for selected bacterial pathogens. No significant differences were observed between the overall bactericidal efficiency for beef-inoculated pathogens based on the uncertainty of the absorbed dose and variations in bacterial counts. This result supported that all three irradiation sources were effective for inactivation of food-borne bacteria and that 7.5 MeV X-rays may be used for food pasteurization.

  12. Efecto bactericida del láser de diodo en periodoncia Bactericidal effects of diode laser in periodontology

    Directory of Open Access Journals (Sweden)

    G. Caccianiga

    2008-04-01

    associated use of laser irradiation and hydrogen peroxide with the goal of reducing the bacterial charge of stocks commonly present in the active periodontal pockets and resistant to the bactericide action of laser irradiation alone such as Prevotella intermedia, Fusobacterium nucleatum, Peptostreptococcus micron. The laboratory method used foresees the following protocol: each bacterial suspension has been exposed to hydrogen peroxide at 3% concentrations and it has been irradiated with laser for 10, 15 or 20 seconds, using sterile 1.5 ml Eppendorf tubes. The results confirm the higher bactericide effectiveness of the combined action of hydrogen peroxide and laser. The microbiological cultivations carried out reveal how, in spite of the bactericide effect, the laser has an insufficient action on bacterial stocks tested if it isn’t associated with hydrogen peroxide. Particularly in the case of the Prevotella intermedia or the Fusobacterium nucleatum the use of just hydrogen peroxide at 3% has offered better results than the laser irradiation alone while the association of both treatments has always offered optimal results. In the case of the Peptostreptococcus micron the use of hydrogen peroxide and laser separately has offered an insufficient reduction of the bacterial count while the association of treatments has increased their bactericide action.

  13. Potent and specific bactericidal effect of juglone (5-hydroxy-1,4-naphthoquinone) on the fire blight pathogen Erwinia amylovora.

    Science.gov (United States)

    Fischer, Thilo Christopher; Gosch, Christian; Mirbeth, Beate; Gselmann, Markus; Thallmair, Veronika; Stich, Karl

    2012-12-12

    A screening of plant quinones for inhibiting effects on the bacterial fire blight pathogen Erwinia amylovora was performed. The most active compound, juglone from walnuts, has a potent and specific bactericidal effect on E. amylovora and minimal inhibitory concentrations of only 2.5-10 μM, with stronger effects at lower, but still physiological, pH values. In vitro tests with juglone and inoculated flowers of apple (Malus domestica) showed an efficacy of 67% in preventing infection. In two years of field tests juglone had variable degrees of efficacy ranging from 40 to 82%, seemingly due to environmental conditions. A phytotoxic reaction to juglone, which is known for its allelopathic effect on plants, was restricted to browning of petals; later fruit russeting was not observed. Juglone is a promising candidate for the development of a new environmentally friendly plant protectant to replace the antibiotic streptomycin currently used in fire blight control. PMID:23163769

  14. Bovine parotid secretory protein: structure, expression and relatedness to other BPI (bactericidal/permeability-increasing protein)-like proteins.

    Science.gov (United States)

    Wheeler, T T; Hood, K; Oden, K; McCracken, J; Morris, C A

    2003-08-01

    Members of the family of BPI (bactericidal/permeability-increasing protein)-like proteins are as yet incompletely characterized, particularly in cattle, where full-length sequence information is available for only three of the 13 family members known from other species. Structural bioinformatic analyses incorporating bovine homologues of several members of the BPI-like protein family, including two forms of bovine parotid secretory protein (PSP), showed that this family is also present in cattle. Expression analyses of several members of the BPI-like protein family in cattle, including PSP (Bsp30), von Ebner's minor salivary gland protein (VEMSGP) and lung-specific X protein (LUNX), showed a restricted pattern of expression, consistent with earlier hypotheses that these proteins function in the innate immune response to bacteria. The possible role of bovine PSP in susceptibility to pasture bloat in cattle is discussed. PMID:12887305

  15. Contribution of the Autolysin AtlA to the Bactericidal Activity of Amoxicillin against Enterococcus faecalis JH2-2▿

    OpenAIRE

    Bravetti, Anne-Lise; Mesnage, Stéphane; Lefort, Agnès; Chau, Françoise; Eckert, Catherine; Garry, Louis; Arthur, Michel; Fantin, Bruno

    2009-01-01

    The bactericidal activity of amoxicillin was investigated against Enterococcus faecalis JH2-2 and against an isogenic mutant deficient in the production of the N-acetylglucosaminidase AtlA. Comparison of the two strains indicated that this autolysin contributes to killing by amoxicillin both in vitro and in a rabbit model of experimental endocarditis.

  16. Short-term storage does not affect the quantitative yield of Mycobacterium tuberculosis in sputum in early-bactericidal-activity studies

    NARCIS (Netherlands)

    Kolwijck, E.; Mitchell, M.; Venter, A.; Friedrich, S.O.; Dawson, R.; Diacon, A.H.

    2013-01-01

    Early-bactericidal-activity (EBA) studies measure the change in mycobacterial load in sputum over time to evaluate antituberculosis drugs. We investigated whether a delay in sputum processing influences the quantitative results of sputum mycobacterial culture. We identified pretreatment smear-positi

  17. Bactericidal activities of health-promoting,food-derived powders against the foodborne pathogens Escherichia coli,listeria monocytogenes, salmonella enterica,and staphylococcus aureus

    Science.gov (United States)

    We evaluated the relative bactericidal activities of 10 presumed health-promoting food-based powders (nutraceuticals) and for comparison, several selected known components of such powders against the following foodborne pathogens: Escherichia coli O157:H7, Salmonella enterica, Listeria monocytogenes...

  18. Serum bactericidal assay for the evaluation of typhoid vaccine using a semi-automated colony-counting method.

    Science.gov (United States)

    Jang, Mi Seon; Sahastrabuddhe, Sushant; Yun, Cheol-Heui; Han, Seung Hyun; Yang, Jae Seung

    2016-08-01

    Typhoid fever, mainly caused by Salmonella enterica serovar Typhi (S. Typhi), is a life-threatening disease, mostly in developing countries. Enzyme-linked immunosorbent assay (ELISA) is widely used to quantify antibodies against S. Typhi in serum but does not provide information about functional antibody titers. Although the serum bactericidal assay (SBA) using an agar plate is often used to measure functional antibody titers against various bacterial pathogens in clinical specimens, it has rarely been used for typhoid vaccines because it is time-consuming and labor-intensive. In the present study, we established an improved SBA against S. Typhi using a semi-automated colony-counting system with a square agar plate harboring 24 samples. The semi-automated SBA efficiently measured bactericidal titers of sera from individuals immunized with S. Typhi Vi polysaccharide vaccines. The assay specifically responded to S. Typhi Ty2 but not to other irrelevant enteric bacteria including Vibrio cholerae and Shigella flexneri. Baby rabbit complement was more appropriate source for the SBA against S. Typhi than complements from adult rabbit, guinea pig, and human. We also examined the correlation between SBA and ELISA for measuring antibody responses against S. Typhi using pre- and post-vaccination sera from 18 human volunteers. The SBA titer showed a good correlation with anti-Vi IgG quantity in the serum as determined by Spearman correlation coefficient of 0.737 (P < 0.001). Taken together, the semi-automated SBA might be efficient, accurate, sensitive, and specific enough to measure functional antibody titers against S. Typhi in sera from human subjects immunized with typhoid vaccines. PMID:27216239

  19. Bactericidal Compounds Controlling Growth of the Plant Pathogen Pseudomonas syringae pv. actinidiae, Which Forms Biofilms Composed of a Novel Exopolysaccharide

    Science.gov (United States)

    Ghods, Shirin; Sims, Ian M.; Moradali, M. Fata

    2015-01-01

    Pseudomonas syringae pv. actinidiae is the major cause of bacterial canker and is a severe threat to kiwifruit production worldwide. Many aspects of the disease caused by P. syringae pv. actinidiae, such as the pathogenicity-relevant formation of a biofilm composed of extracellular polymeric substances (EPSs), are still unknown. Here, a highly virulent strain of P. syringae pv. actinidiae, NZ V-13, was studied with respect to biofilm formation and architecture using a flow cell system combined with confocal laser scanning microscopy. The biofilm formed by P. syringae pv. actinidiae NZ V-13 was heterogeneous, consisting of a thin cellular base layer 5 μm thick and microcolonies with irregular structures. The major component of the EPSs produced by P. syringae pv. actinidiae NZ V-13 bacteria was isolated and identified to be an exopolysaccharide. Extensive compositional and structural analysis showed that rhamnose, fucose, and glucose were the major constituents, present at a ratio of 5:1.5:2. Experimental evidence that P. syringae pv. actinidiae NZ V-13 produces two polysaccharides, a branched α-d-rhamnan with side chains of terminal α-d-Fucf and an α-d-1,4-linked glucan, was obtained. The susceptibility of the cells in biofilms to kasugamycin and chlorine dioxide was assessed. About 64 and 73% of P. syringae pv. actinidiae NZ V-13 cells in biofilms were killed when kasugamycin and chlorine dioxide were used at 5 and 10 ppm, respectively. Kasugamycin inhibited the attachment of P. syringae pv. actinidiae NZ V-13 to solid surfaces at concentrations of 80 and 100 ppm. Kasugamycin was bacteriostatic against P. syringae pv. actinidiae NZ V-13 growth in the planktonic mode, with the MIC being 40 to 60 ppm and a bactericidal effect being found at 100 ppm. Here we studied the formation, architecture, and composition of P. syringae pv. actinidiae biofilms as well as used the biofilm as a model to assess the efficacies of bactericidal compounds. PMID:25841017

  20. Comparison of methods for evaluation of the bactericidal activity of copper-sputtered surfaces against methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Rio, Laura; Kusiak-Nejman, Ewelina; Kiwi, John; Bétrisey, Bertrand; Pulgarin, César; Trampuz, Andrej; Bizzini, Alain

    2012-12-01

    Bacteria can survive on hospital textiles and surfaces, from which they can be disseminated, representing a source of health care-associated infections (HCAIs). Surfaces containing copper (Cu), which is known for its bactericidal properties, could be an efficient way to lower the burden of potential pathogens. The antimicrobial activity of Cu-sputtered polyester surfaces, obtained by direct-current magnetron sputtering (DCMS), against methicillin-resistant Staphylococcus aureus (MRSA) was tested. The Cu-polyester microstructure was characterized by high-resolution transmission electron microscopy to determine the microstructure of the Cu nanoparticles and by profilometry to assess the thickness of the layers. Sputtering at 300 mA for 160 s led to a Cu film thickness of 20 nm (100 Cu layers) containing 0.209% (wt/wt) polyester. The viability of MRSA strain ATCC 43300 on Cu-sputtered polyester was evaluated by four methods: (i) mechanical detachment, (ii) microcalorimetry, (iii) direct transfer onto plates, and (iv) stereomicroscopy. The low efficacy of mechanical detachment impeded bacterial viability estimations. Microcalorimetry provided only semiquantitative results. Direct transfer onto plates and stereomicroscopy seemed to be the most suitable methods to evaluate the bacterial inactivation potential of Cu-sputtered polyester surfaces, since they presented the least experimental bias. Cu-polyester samples sputtered for 160 s by DCMS were further tested against 10 clinical MRSA isolates and showed a high level of bactericidal activity, with a 4-log(10) reduction in the initial MRSA load (10(6) CFU) within 1 h. Cu-sputtered polyester surfaces might be of use to prevent the transmission of HCAI pathogens. PMID:22983970

  1. Effect of ZnO morphology on affecting bactericidal property of ultra high molecular weight polyethylene biocomposite.

    Science.gov (United States)

    Sharma, Rajeev Kumar; Agarwal, Meenakshi; Balani, Kantesh

    2016-05-01

    Bacterial infection of implants can be controlled by selective trapping of bacteria, followed with consequent killing by targeted antibacterial agents. Herein, the role of various ZnO morphologies, viz. micro-rods (R), nanoparticles (NP), and micro-disks (D) on antibacterial efficacy of ZnO via release of Zn(2+) and H2O2 is assessed, both as isolated powders and via incorporating them in cytocompatible ultra high molecular weight polyethylene (UHMWPE). Though ZnO is antibacterial, interestingly, all ZnO morphologies elicited a supportive growth of gram-negative bacteria (Escherichia coli) in culture medium (until 28-35μg/ml). But, all ZnO morphologies did elicit bactericidal effect on gram positive bacteria (Staphylococcus aureus or Staphylococcus epidermidis) both in culture medium (for 0-2.5μg/ml) or when incorporated (5-20wt.%) into UHMWPE. The bactericidal mechanisms were quantified for various ZnO morphologies via: (i) H2O2 production, (ii) Zn(2+) release, and (iii) the presence of surface oxygen vacancies. On one hand, where only ZnO(NP) elicited release of H2O2 in the absence of light, maximum Zn(2+) release was elicited by ZnO(D). Interestingly, when ZnO is incorporated as reinforcement (5-20wt.%), its antibacterial action against E. coli was vividly observed due to selective proliferation of bacteria only on friendly UHMWPE matrix. Hence, luring bacteria on affable UHMWPE surface can be complemented with their targeted killing by ZnO present in composite. PMID:26952491

  2. A STUDY OF THE BACTERICIDAL PROPERTY OF AQUEOUS EXTRACT OF MEDICINAL PLANTS-ACACIA CATECHU AND FISCUS HISPIDA USED IN THE TRADITIONAL SYSTEM OF MEDICINE IN MANIPUR

    Directory of Open Access Journals (Sweden)

    Lokhendro Singh

    2014-07-01

    Full Text Available OBJECTIVE: To find out the bactericidal effect of extract of the Acacia catechu and Ficus hispida which are commonly used by the local quacks for the treatment of diarrhea and dysentery in the villages of the state of Manipur where the medical facilities are not available. METHODS: The plant barks are collected from different parts of Manipur during the period of March 2006 to February 2007, dried at room temperature; make powder in the grinder and soxhlated at low temperature to get the yield (extract. In case of Acacia catechu dried power form is available in the market. The powder is soxhlated to get the yield. These extracts are tested for the bactericidal effect in serial dilutions against the known strain of Staphylococcus aureus (ATCC 25923 and Escherichia coli (ATCC 25922 and incubated at 370C overnight. After overnight incubation, the tubes are checked for the growth of the organisms and from the tubes sub cultures are made serially corresponding to the dilutions on to the Blood agar, Mac Conkey and Nutrient agar media, incubated at 370C overnight. After overnight incubation, the dilution where the growth of the organisms does not occurred, are noted and tabulated. RESULT: The aqueous extract of Acacia catechu shows bactericidal effect up to the dilution of 1:8 whereas the aqueous extract of Ficus hispida shows no bactericidal effect even at higher concentration. CONCLUSION: These plants extract have been using for the treatment of ailments in the villages of the state of Manipur by the local quacks since time immemorial. In this study it has seen that Acacia catechu has the medicinal properties whereas Ficus hispida has no bactericidal property though the plant has other medicinal properties. It is therefore, necessary to do further studies to identify the ingredients present in this two plants for safe use and large scale production in the state.

  3. Expression of the K54 and O4 specific antigen has opposite effects on the bactericidal activity of squalamine against an extraintestinal isolate of Escherichia coli.

    Science.gov (United States)

    Russo, T A; Mylotte, D

    1998-05-15

    Squalamine is a novel cationic steroid that possesses potent, broad spectrum, antimicrobial activity. Recent data suggests that squalamine or related compounds may be present and important in host resistance to infection in the urinary tract. Therefore, the role of the K54 capsule and the O4 specific antigen moiety of the lipopolysaccharide in protecting an extraintestinal isolate of Escherichia coli against the bactericidal activity of this novel antimicrobial compound was studied. The O4 specific antigen was important for protection against squalamine. Surprisingly, in contrast, the presence of the K54 antigen enhanced the bactericidal activity of squalamine. This is the first example, to our knowledge, in which an established virulence trait, the K54 capsule, may be detrimental to an infecting pathogen under certain circumstances. PMID:9627966

  4. Irradiance and Temperature Influence the Bactericidal Effect of 460-Nanometer Light-Emitting Diodes on Salmonella in Orange Juice.

    Science.gov (United States)

    Ghate, Vinayak; Kumar, Amit; Zhou, Weibiao; Yuk, Hyun-Gyun

    2016-04-01

    Blue light-emitting diodes (LEDs) have been known to produce an antibacterial effect on various pathogenic bacteria. To extend this application to foods, blue 460-nm LEDs were evaluated for their antibacterial effect on Salmonella in orange juice. A cocktail of Salmonella enterica serovars Gaminara, Montevideo, Newport, Typhimurium, and Saintpaul was inoculated into pasteurized orange juice and illuminated with 460-nm LEDs at irradiances of 92, 147.7, and 254.7 mW/cm(2) and temperatures of 4, 12, and 20°C. Subsequently, linear, Weibull, and Gompertz models were fitted to the resultant survival curves. The color of the orange juice during illumination was also monitored. It was observed that irradiance and temperature both influenced the inactivation of Salmonella, which ranged from 2 to 5 log CFU/ml. The inactivation kinetics was best described by the Weibull model. An irradiance of 92 mW/cm(2) and temperatures of 12 and 20°C were the most bactericidal combinations, with D-values of 1,580 and 2,013 J/cm(2), respectively. Significant color changes were also observed after illumination; these changes could be minimized by choosing appropriate irradiance and temperature. These results demonstrate the potential of 460-nm LEDs for the preservation of fruit juices in the retail markets and their utility in minimizing the risk of salmonellosis. PMID:27052858

  5. Electrochemical synthesis of multi-armed CuO nanoparticles and their remarkable bactericidal potential against waterborne bacteria

    International Nuclear Information System (INIS)

    Copper (II) oxide multi-armed nanoparticles composed of 500–1000 nm long radiating nanospicules with 100–200 nm width near the base and 50–100 nm width at the tapered ends and ∼25 nm thickness were synthesized by electrochemical deposition in the presence of an oxidant followed by calcination at 150 °C. The nanoparticles were characterized using SEM/EDX for morphology and composition, Raman spectroscopy for compound identification, and broth culture method for antibacterial efficacy. The CuO nanoparticles have shown remarkable bactericidal efficacy against Gram-positive and -negative waterborne disease causing bacteria like Escherichia coli, Salmonella typhi, staphylococcus aureus and Bacillus subtilis. E. coli has been chosen as representative species for waterborne disease causing bacteria. In antibacterial tests 500 μg/mL nano CuO killed 3 × 108 CFU/mL E. coli bacteria within 4 h of exposure. Moreover, 8.3 × 106 CFU/mL E. coli were killed by 100 and 10 μg/mL nano CuO within 15 min and 4 h of exposure, respectively. Antibacterial activity of nano CuO has been found many-fold compared with commercial bulk CuO. The fate of nanoparticles after antibacterial test has also been studied. The synthesized CuO nanoparticles are expected to have potential antibacterial applications in water purification and in paints and coatings used on frequently touched surfaces and fabrics in hospital settings.

  6. The Human Antimicrobial Protein Bactericidal/Permeability-Increasing Protein (BPI) Inhibits the Infectivity of Influenza A Virus

    Science.gov (United States)

    Pinkenburg, Olaf; Meyer, Torben; Bannert, Norbert; Norley, Steven; Bolte, Kathrin; Czudai-Matwich, Volker; Herold, Susanne; Gessner, André; Schnare, Markus

    2016-01-01

    In addition to their well-known antibacterial activity some antimicrobial peptides and proteins (AMPs) display also antiviral effects. A 27 aa peptide from the N-terminal part of human bactericidal/permeability-increasing protein (BPI) previously shown to harbour antibacterial activity inhibits the infectivity of multiple Influenza A virus strains (H1N1, H3N2 and H5N1) the causing agent of the Influenza pneumonia. In contrast, the homologous murine BPI-peptide did not show activity against Influenza A virus. In addition human BPI-peptide inhibits the activation of immune cells mediated by Influenza A virus. By changing the human BPI-peptide to the sequence of the mouse homologous peptide the antiviral activity was completely abolished. Furthermore, the human BPI-peptide also inhibited the pathogenicity of the Vesicular Stomatitis Virus but failed to interfere with HIV and measles virus. Electron microscopy indicate that the human BPI-peptide interferes with the virus envelope and at high concentrations was able to destroy the particles completely. PMID:27273104

  7. Ambroxol inhibits mucoid conversion of Pseudomonas aeruginosa and contributes to the bactericidal activity of ciprofloxacin against mucoid P. aeruginosa biofilms.

    Science.gov (United States)

    Wang, Wenlei; Yu, Jialin; He, Yu; Wang, Zhengli; Li, Fang

    2016-07-01

    Pseudomonas aeruginosa is an opportunistic human pathogen that can cause severe infections in immunocompromised individuals. Because it forms biofilms, which protect against host immune attack and increase resistance to conventional antibiotics, mucoid P. aeruginosa is nearly impossible to eradicate. Moreover, mucoid conversion of P. aeruginosa in cystic fibrosis (CF) patients leads to poor outcomes. This conversion is mainly due to mucA gene mutation, which is thought to be induced by polymorphonuclear leukocytes (PMNs) and the reactive oxygen species they release. Ambroxol, a mucolytic agent with antioxidant characteristics, is used clinically, and this compound has recently been demonstrated to possess anti-biofilm properties. In this study, we found that ambroxol inhibits the H2 O2 -mediated conversion of P. aeruginosa from a non-mucoid to a mucoid phenotype, an effect that is due to its antioxidant property against H2 O2 . Furthermore, the bactericidal activity of ciprofloxacin against mucoid P. aeruginosa biofilms was increased in vitro when used in combination with ambroxol. PMID:27102839

  8. Antibodies recognizing a variety of different structural motifs on meningococcal Lip antigen fail to demonstrate bactericidal activity.

    Science.gov (United States)

    Tinsley, C R; Virji, M; Heckels, J E

    1992-11-01

    The neisserial Lip antigen is a conserved antigen associated with the pathogenic Neisseria species, and is composed of multiple repeats of a consensus pentapeptide. A series of monoclonal antibodies reacting with meningococcal Lip antigen were subjected to epitope mapping, using solid-phase synthetic peptides based on the consensus repeat sequence. The antibodies were found to recognize different continuous epitopes based on the consensus sequence. One monoclonal antibody was utilized in affinity chromatography to obtain purified Lip antigen and the antigen was used for immunization of mice. The resulting antisera did not recognize Lip antigen on Western blots but reacted specifically with Lip antigen in immune precipitation experiments, indicating that the predominant polyclonal immune response was directed against conformational epitopes. Despite the diversity of both continuous and conformational epitopes recognized by the antibodies produced, none of the antibodies demonstrated the ability to promote complement-mediated bactericidal activity. Thus despite its initial apparent promise as a potential vaccine candidate the case for the inclusion of Lip antigen in vaccine formulation cannot be supported at present. PMID:1282535

  9. Biological and bactericidal properties of Ag-doped bioactive glass in a natural extracellular matrix hydrogel with potential application in dentistry

    OpenAIRE

    Y-Y Wang; X Chatzistavrou; D Faulk; Badylak, S; Zheng, L; S. Papagerakis; Ge, L.; H. Liu; Papagerakis, P.

    2015-01-01

    The aim of this study was the fabrication and evaluation of a novel bioactive and bactericidal material, which could have applications in dentistry by supporting tissue regeneration and killing oral bacteria. Our hypothesis was that a new scaffold for pulp-dentin tissue engineering with enhanced antibacterial activity could be obtained by associating extracellular matrix derived from porcine bladder with an antibacterial bioactive glass. Our study combines in vitro approaches and ectopic impl...

  10. Intranasal Delivery of Group B Meningococcal Native Outer Membrane Vesicle Vaccine Induces Local Mucosal and Serum Bactericidal Antibody Responses in Rabbits

    OpenAIRE

    Shoemaker, David R.; Saunders, Nancy B.; Brandt, Brenda L.; Moran, E. Ellen; LaClair, Andrew D.; Zollinger, Wendell D.

    2005-01-01

    We have previously shown that intranasal immunization of mice with meningococcal native outer membrane vesicles (NOMV) induces both a good local mucosal antibody response and a good systemic bactericidal antibody response. However, in the intranasal mouse model, some of the NOMV entered the lung and caused an acute granulocytic response. We therefore developed an alternate animal model using the rabbit. This model reduces the probability of lung involvement and more closely mimics intranasal ...

  11. Bactericidal Activities of Daptomycin, Quinupristin-Dalfopristin, and Linezolid against Vancomycin-Resistant Staphylococcus aureus in an In Vitro Pharmacodynamic Model with Simulated Endocardial Vegetations

    OpenAIRE

    Cha, Raymond; Brown, William J.; Rybak, Michael J.

    2003-01-01

    In search of treatment alternatives against vancomycin-resistant S. aureus (VRSA), an in vitro pharmacodynamic model with simulated endocardial vegetations incorporating protein and a high inoculum was used to simulate daptomycin, linezolid, quinupristin-dalfopristin, and vancomycin against the Michigan VRSA strain. Daptomycin and quinupristin-dalfopristin exhibited the greatest bacterial reductions, and all tested agents except vancomycin exhibited bactericidal activity against the VRSA.

  12. Bactericidal interactions of a beta-lactam and beta-lactamase inhibitors in experimental Pseudomonas aeruginosa endocarditis caused by a constitutive overproducer of type Id beta-lactamase.

    OpenAIRE

    Bayer, A S; Selecky, M; Babel, K; Hirano, L; Yih, J; Parr, T R

    1987-01-01

    We investigated the in vitro and in vivo effects of a combination of a beta-lactam (ceftazidime) and a beta-lactamase inhibitor (dicloxacillin) to synergistically kill a ceftazidime-resistant variant, Pseudomonas aeruginosa PA-48, which overproduces type Id cephalosporinase constitutively. In vitro, dicloxacillin plus ceftazidime exerted bactericidal synergy at approximately 10(5) CFU/ml of inoculum (but not at approximately 10(7)-CFU inoculum), whereas other beta-lactamase inhibitors (sulbac...

  13. Silver-nanoparticle based bactericidal coating for poly(glycolide-co-lactide) suture threads obtained by the method of laser ablation of bulk targets in alcohol solutions

    Science.gov (United States)

    Babkina, O. V.; Svetlichnyi, V. A.; Lapin, I. N.; Novikov, V. T.; Nemoikina, A. L.

    2013-09-01

    A laser ablation method is suggested to synthesize a dispersion of silver nanoparticles to create a bactericidal coating of biodegradable suture material from poly(glycolide-co-lactide) using a bulk target immersed in a liquid. The laser ablation method with nanosecond excitation by a Nd:YAG laser (1064 nm, 7 ns) is used to obtain silver nanoparticles with mean diameter of 27 nm in ethanol. Nanoparticle concentrations up to 12 mass% were obtained on the polymer surfaces by multiple impregnation.

  14. Evaluation of the bactericidal efficacy of three different alcohol hand rubs against clinical isolates of Staphylococcus aureus using an ex vivo carrier test.

    Science.gov (United States)

    Cheeseman, K E; Denyer, S P; Hosein, I K; Williams, G J; Maillard, J-Y

    2011-01-01

    We tested the efficacy of three alcohol hand rubs (AHRs) against Staphylococcus aureus using an ex vivo carrier test method and investigated the residual activity of AHRs and the effect of mechanical rubbing. A much longer contact time was required for the AHRs to achieve a bactericidal effect using the ex vivo test (between 10 and >20 min) compared with the in vitro test. Mechanical rubbing was found to increase the efficacy of the AHR compared to a rubbing control. Since the AHRs had no residual activity, the bactericidal effect achieved using the ex vivo test with contact times greater than the evaporation times (15 s) is unlikely to be achieved in practice. In view of such findings it is unlikely that AHRs are able to achieve a significant bactericidal effect (≥4 log(10) reduction) in practice, suggesting that contamination on the hands of healthcare workers (HCWs) may not be reduced enough to overcome the risk of cross-contamination and healthcare-associated infection. Since the AHRs had no residual effect they would be unable to prevent recolonisation of the hands of HCWs. PMID:21130519

  15. Destabilization of α-Helical Structure in Solution Improves Bactericidal Activity of Antimicrobial Peptides: Opposite Effects on Bacterial and Viral Targets.

    Science.gov (United States)

    Ulaeto, David O; Morris, Christopher J; Fox, Marc A; Gumbleton, Mark; Beck, Konrad

    2016-04-01

    We have previously examined the mechanism of antimicrobial peptides on the outer membrane of vaccinia virus. We show here that the formulation of peptides LL37 and magainin-2B amide in polysorbate 20 (Tween 20) results in greater reductions in virus titer than formulation without detergent, and the effect is replicated by substitution of polysorbate 20 with high-ionic-strength buffer. In contrast, formulation with polysorbate 20 or high-ionic-strength buffer has the opposite effect on bactericidal activity of both peptides, resulting in lesser reductions in titer for both Gram-positive and Gram-negative bacteria. Circular dichroism spectroscopy shows that the differential action of polysorbate 20 and salt on the virucidal and bactericidal activities correlates with the α-helical content of peptide secondary structure in solution, suggesting that the virucidal and bactericidal activities are mediated through distinct mechanisms. The correlation of a defined structural feature with differential activity against a host-derived viral membrane and the membranes of both Gram-positive and Gram-negative bacteria suggests that the overall helical content in solution under physiological conditions is an important feature for consideration in the design and development of candidate peptide-based antimicrobial compounds. PMID:26824944

  16. Green synthesis and characterization of Carica papaya leaf extract coated silver nanoparticles through X-ray diffraction, electron microscopy and evaluation of bactericidal properties.

    Science.gov (United States)

    Banala, Rajkiran Reddy; Nagati, Veera Babu; Karnati, Pratap Reddy

    2015-09-01

    The evolution of nanotechnology and the production of nanomedicine from various sources had proven to be of intense value in the field of biomedicine. The smaller size of nanoparticles is gaining importance in research for the treatment of various diseases. Moreover the production of nanoparticles is eco-friendly and cost effective. In the present study silver nanoparticles were synthesized from Carica papaya leaf extract (CPL) and characterized for their size and shape using scanning electron microscopy and transmission electron microscopy, respectively. Fourier transform infrared spectroscopy (FTIR), Energy dispersive X-ray spectroscopy (EDS/EDX) and X-ray diffraction spectroscopy (XRD) were conducted to determine the concentration of metal ions, the shape of molecules. The bactericidal activity was evaluated using Luria Bertani broth cultures and the minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) were estimated using turbidimetry. The data analysis showed size of 50-250 nm spherical shaped nanoparticles. The turbidimetry analysis showed MIC and MBC was >25 μg/mL against both Gram positive and Gram negative bacteria in Luria Bertani broth cultures. In summary the synthesized silver nanoparticles from CPL showed acceptable size and shape of nanoparticles and effective bactericidal activity. PMID:26288570

  17. Complement-mediated bactericidal activity of human antibodies to poly alpha 2-->8 N-acetylneuraminic acid, the capsular polysaccharide of Neisseria meningitidis serogroup B.

    Science.gov (United States)

    Mandrell, R E; Azmi, F H; Granoff, D M

    1995-11-01

    Serum antibodies to Neisseria meningitidis group B (MenB) polysaccharide are reported not to elicit bacteriolysis in the presence of human complement. To reexamine this question, we evaluated the ability of two human IgM anti-MenB polysaccharide monoclonal antibodies (MAbs) and seven human MenB polysaccharide-reactive human IgM paraproteins to elicit bacteriolysis. In the presence of human complement, both MAbs and five of the seven paraproteins were bactericidal at antibody concentrations of 0.25-9.6 micrograms/mL (50% killing). Activity of the respective antibodies was enhanced 200- to > 10,000-fold when rabbit complement was used instead of human complement. With rabbit complement, the bactericidal activity of human IgM polyclonal antibody or MAb to Haemophilus influenzae type b (Hib) polysaccharide but not human IgG polyclonal antibody or MAb to Hib polysaccharide was similarly augmented. Thus, for both MenB and Hib, IgM antipolysaccharide antibodies elicit complement-mediated bactericidal activity in the presence of human complement, and the use of rabbit complement yields spuriously high activity. PMID:7594665

  18. Interactions of Quinupristin-Dalfopristin with Eight Other Antibiotics as Measured by Time-Kill Studies with 10 Strains of Staphylococcus aureus for Which Quinupristin-Dalfopristin Alone Was Not Bactericidal

    OpenAIRE

    Fuchs, Peter C.; Barry, Arthur L.; Brown, Steven D.

    2001-01-01

    Quinupristin-dalfopristin (Q-D) and eight other antimicrobial agents were tested alone and in combination with Q-D in time-kill studies against 10 strains of macrolide-lincosamide-streptogramin B-resistant Staphylococcus aureus. Although Q-D is normally a bactericidal drug, it was only bacteriostatic for these isolates. Gentamicin alone was bactericidal against 7 of the 10 strains, and Q-D did not alter that killing effect. However, when vancomycin, cefepime, ceftazidime, imipenem, piperacill...

  19. Periowave demonstrates bactericidal activity against periopathogens and leads to improved clinical outcomes in the treatment of adult periodontitis

    Science.gov (United States)

    Street, Cale N.; Andersen, Roger; Loebel, Nicolas G.

    2009-02-01

    Periodontitis affects half of the U.S. population over 50, and is the leading cause of tooth loss after 35. It is believed to be caused by growth of complex bacterial biofilms on the tooth surface below the gumline. Photodynamic therapy, a technology used commonly in antitumor applications, has more recently been shown to exhibit antimicrobial efficacy. We have demonstrated eradication of the periopathogens Porphyromonas gingivalis, Fusobacterium nucleatum, and Aggregatibacter actinomycetemcomitans in vitro using PeriowaveTM; a commercial photodisinfection system. In addition, several clinical studies have now demonstrated the efficacy of this treatment. A pilot study in the U.S. showed that 68% of patients treated with PeriowaveTM adjunctively to scaling and root planing (SRP) showed clinical attachment level increase of >1 mm, as opposed to 30% with SRP alone. In a subsequent larger study, a second PeriowaveTM treatment 6 weeks after initial treatment led to pocket depth improvements of >1.5 mm in 89% of patients. Finally, in the most recent multicenter, randomized, examiner-blinded study conducted on 121 subjects in Canada, PeriowaveTM treatment produced highly significant gains in attachment level (0.88 mm vs. 0.57 mm; p=0.003) and pocket depth (0.87 mm vs. 0.63 mm; p=0.01) as compared to SRP alone. In summary, PeriowaveTM demonstrated strong bactericidal activity against known periopathogens, and treatment of periodontitis using this system produced significantly better clinical outcomes than SRP alone. This, along with the absence of any adverse events in patients treated to date demonstrates that PDT is a safe and effective treatment for adult chronic periodontitis.

  20. First-in-Class Inhibitors of Sulfur Metabolism with Bactericidal Activity against Non-Replicating M. tuberculosis.

    Science.gov (United States)

    Palde, Prakash B; Bhaskar, Ashima; Pedró Rosa, Laura E; Madoux, Franck; Chase, Peter; Gupta, Vinayak; Spicer, Timothy; Scampavia, Louis; Singh, Amit; Carroll, Kate S

    2016-01-15

    Development of effective therapies to eradicate persistent, slowly replicating M. tuberculosis (Mtb) represents a significant challenge to controlling the global TB epidemic. To develop such therapies, it is imperative to translate information from metabolome and proteome adaptations of persistent Mtb into the drug discovery screening platforms. To this end, reductive sulfur metabolism is genetically and pharmacologically implicated in survival, pathogenesis, and redox homeostasis of persistent Mtb. Therefore, inhibitors of this pathway are expected to serve as powerful tools in its preclinical and clinical validation as a therapeutic target for eradicating persisters. Here, we establish a first functional HTS platform for identification of APS reductase (APSR) inhibitors, a critical enzyme in the assimilation of sulfate for the biosynthesis of cysteine and other essential sulfur-containing molecules. Our HTS campaign involving 38 350 compounds led to the discovery of three distinct structural classes of APSR inhibitors. A class of bioactive compounds with known pharmacology displayed potent bactericidal activity in wild-type Mtb as well as MDR and XDR clinical isolates. Top compounds showed markedly diminished potency in a conditional ΔAPSR mutant, which could be restored by complementation with Mtb APSR. Furthermore, ITC studies on representative compounds provided evidence for direct engagement of the APSR target. Finally, potent APSR inhibitors significantly decreased the cellular levels of key reduced sulfur-containing metabolites and also induced an oxidative shift in mycothiol redox potential of live Mtb, thus providing functional validation of our screening data. In summary, we have identified first-in-class inhibitors of APSR that can serve as molecular probes in unraveling the links between Mtb persistence, antibiotic tolerance, and sulfate assimilation, in addition to their potential therapeutic value. PMID:26524379

  1. Development of Titanium Dioxide (TiO2 ) Nanocoatings on Food Contact Surfaces and Method to Evaluate Their Durability and Photocatalytic Bactericidal Property.

    Science.gov (United States)

    Yemmireddy, Veerachandra K; Farrell, Glenn D; Hung, Yen-Con

    2015-08-01

    Titanium dioxide (TiO2 ) is a well-known photocatalyst for its excellent bactericidal property under UVA light. The purpose of this study was to develop physically stable TiO2 coatings on food contact surfaces using different binding agents and develop methods to evaluate their durability and microbicidal property. Several types of organic and inorganic binders such as polyvinyl alcohol, polyethylene glycol, polyurethane, polycrylic, sodium and potassium silicates, shellac resin, and other commercial binders were used at 1:1 to 1:16 nanoparticle to binder weight ratios to develop a formulation for TiO2 coating on stainless steel surfaces. Among the tested binders, polyurethane, polycrylic, and shellac resin were found to be physically more stable when used in TiO2 coating at 1:4 to 1:16 weight ratio. The physical stability of TiO2 coatings was determined using adhesion strength and scratch hardness tests by following standard ASTM procedures. Further, wear resistance of the coatings was evaluated based on a simulated cleaning procedure used in food processing environments. TiO2 coating with polyurethane at a 1:8 nanoparticle to binder weight ratio showed the highest scratch hardness (1.08 GPa) followed by coating with polycrylic (0.68 GPa) and shellac (0.14 GPa) binders. Three different techniques, namely direct spreading, glass cover-slip, and indented coupon were compared to determine the photocatalytic bactericidal property of TiO2 coatings against Escherichia coli 0157:H7 at 2 mW/cm(2) UVA light intensity. Under the tested conditions, the indented coupon technique was found to be the most appropriate method to determine the bactericidal property of TiO2 coatings and showed a reduction of 3.5 log CFU/cm(2) in 2 h. PMID:26189653

  2. Immunization with synthetic peptides containing epitopes of the class 1 outer-membrane protein of Neisseria meningitidis: production of bactericidal antibodies on immunization with a cyclic peptide.

    Science.gov (United States)

    Christodoulides, M; McGuinness, B T; Heckels, J E

    1993-08-01

    The class 1 outer-membrane protein of Neisseria meningitidis is the target for subtype-specific, bactericidal monoclonal antibodies (mAbs). The epitopes recognized by these antibodies have been mapped previously to linear peptides corresponding to the sequences thought to be exposed at the apices of surface-exposed loops of the protein. In this work several synthetic peptides containing the subtype Pl.16b epitope have been synthetized with the aim of inducing a polyclonal immune response resembling the reactivity of the mAbs. Initially, peptides of 9 and 15 amino acid residues were synthesized and used for immunization after coupling to a carrier protein. The reactivity of the resulting antisera, with synthetic linear decapeptides, resembled that seen in previous epitope mapping experiments with the protective mAbs. However, despite the induction of antibodies having the desired specificity, the antisera reacted poorly with the native protein in outer membranes, and were non-bactericidal. A 36mer peptide, consisting of the entire surface-exposed loop 4 of the class 1 protein was then synthesized and used for immunization as (i) free peptide, (ii) peptide coupled to carrier and (iii) peptide subjected to cyclization, in an attempt to restrict it to conformations that might more closely resemble the native loop structure. In contrast to antisera raised against linear peptides, antibodies raised by immunization with the 36mer cyclic peptide, did not react with linear peptides recognized by the mAbs, but instead appeared to recognize conformational determinants. This antiserum promoted complement-mediated bactericidal killing of the homologous meningococcal strain, demonstrating the potential of synthetic peptide immunogens for inducing a protective immune response against group B meningococci. PMID:7691983

  3. Aging Enhances the Production of Reactive Oxygen Species and Bactericidal Activity in Peritoneal Macrophages by Upregulating Classical Activation Pathways

    Energy Technology Data Exchange (ETDEWEB)

    Smallwood, Heather S.; López-Ferrer, Daniel; Squier, Thomas C.

    2011-10-07

    Maintenance of macrophages in their basal state and their rapid activation in response to pathogen detection are central to the innate immune system, acting to limit nonspecific oxidative damage and promote pathogen killing following infection. To identify possible age-related alterations in macrophage function, we have assayed the function of peritoneal macrophages from young (3–4 months) and aged (14–15 months) Balb/c mice. In agreement with prior suggestions, we observe age-dependent increases in the extent of recruitment of macrophages into the peritoneum, as well as ex vivo functional changes involving enhanced nitric oxide production under resting conditions that contribute to a reduction in the time needed for full activation of senescent macrophages following exposure to lipopolysaccharides (LPS). Further, we observe enhanced bactericidal activity following Salmonella uptake by macrophages isolated from aged Balb/c mice in comparison with those isolated from young animals. Pathways responsible for observed phenotypic changes were interrogated using tandem mass spectrometry, which identified age-dependent increases in levels of proteins linked to immune cell pathways under basal conditions and following LPS activation. Immune pathways upregulated in macrophages isolated from aged mice include proteins critical to the formation of the immunoproteasome. Detection of these latter proteins is dramatically enhanced following LPS exposure for macrophages isolated from aged animals; in comparison, the identification of immunoproteasome subunits is insensitive to LPS exposure for macrophages isolated from young animals. Consistent with observed global changes in the proteome, quantitative proteomic measurements indicate that there are age-dependent abundance changes involving specific proteins linked to immune cell function under basal conditions. LPS exposure selectively increases the levels of many proteins involved in immune cell function in aged Balb/c mice

  4. Randomized Dose-Ranging Study of the 14-Day Early Bactericidal Activity of Bedaquiline (TMC207) in Patients with Sputum Microscopy Smear-Positive Pulmonary Tuberculosis

    OpenAIRE

    Diacon, Andreas H; Dawson, Rodney; Von Groote-Bidlingmaier, Florian; Symons, Gregory; Venter, Amour; Donald, Peter R.; Conradie, Almari; Erondu, Ngozi; Ginsberg, Ann M.; Egizi, Erica; Winter, Helen; De Becker, Piet; Mendel, Carl M.

    2013-01-01

    Bedaquiline is a new antituberculosis agent targeting ATP synthase. This randomized, double-blinded study enrolling 68 sputum smear-positive pulmonary tuberculosis patients evaluated the 14-day early bactericidal activity of daily doses of 100 mg, 200 mg, 300 mg, and 400 mg bedaquiline, preceded by loading doses of 200 mg, 400 mg, 500 mg, and 700 mg, respectively, on the first treatment day and 100 mg, 300 mg, 400 mg, and 500 mg on the second treatment day. All groups showed activity with a m...

  5. Identification and characterization of a phospholipase A2 from the venom of the Saw-scaled viper: Novel bactericidal and membrane damaging activities.

    Science.gov (United States)

    Perumal Samy, Ramar; Gopalakrishnakone, P; Bow, Ho; Puspharaj, Peter N; Chow, Vincent T K

    2010-12-01

    Phospholipase A(2) (PLA(2)), a common toxic component of snake venom, has been implicated in various pharmacological effects. In this study, a basic myotoxic PLA(2), named EcTx-I was isolated from Echis carinatus snake venom by using gel filtration on Superdex G-75, and reverse phase HPLC on C18 and C8 Sepharose columns. PLA(2), EcTx-I was 13,861.72 molecular weight as estimated by MALDI-TOF (15 kD by SDS-PAGE), and consisted of 121 amino acid residues cross-linked by seven disulfide bonds. The N-terminal sequences revealed significant homology with basic myotoxic PLA(2)s from other snake venoms. The purified PLA(2) EcTx-I was evaluated (250 μg/ml) for bactericidal activity of a wide variety of human pathogens against Burkholderia pseudomallei (KHW&TES), Enterobacter aerogenes, Escherichia coli, Proteus vulgaris, Proteus mirabilis, Pseudomonas aeruginosa and Staphylococcus aureus. EcTx-I showed strong antibacterial activity against B. pseudomallei (KHW) and E. aerogenes among the tested bacteria. Other Gram-negative and Gram-positive bacteria showed only a moderate effect. However, the Gram-positive bacterium E. aerogenes failed to show any effect on EcTx-I protein at tested doses. The most significant bacteriostatic and bactericidal effect of EcTx-I was observed at MICs of >15 μg/ml against (B. pseudomallei, KHW) and MICs >30 μg/ml against E. aerogenes. Mechanisms of bactericidal and membrane damaging effects were proved by ultra-structural analysis. EcTx-I was able to induce cytotoxicity on THP-1 cells in vitro as well as lethality in BALB/c mice. EcTx-I also induced mild myotoxic effects on mouse skin, but was devoid of hemolytic effects on human erythrocytes up to 500 μg/ml. It is shown that the toxic effect induced by E. carinatus venom is due to the presence of myotoxic PLA(2) (EcTx-I). The result also corroborates the hypothesis of an association between toxic and enzymatic domains. In conclusion, EcTx-I displays a heparin binding C-terminal region

  6. Surface-Mediated Release of a Small-Molecule Modulator of Bacterial Biofilm Formation: A Non-Bactericidal Approach to Inhibiting Biofilm Formation in Pseudomonas aeruginosa

    OpenAIRE

    Broderick, Adam H.; Breitbach, Anthony S.; Frei, Reto; Blackwell, Helen E.; Lynn, David M.

    2013-01-01

    We report an approach to preventing bacterial biofilm formation that is based on the surface-mediated release of 5,6-dimethyl-2-aminobenzimidazole (DMABI), a potent and non-bactericidal small-molecule inhibitor of bacterial biofilm growth. Our results demonstrate that DMABI can be encapsulated in thin films of a model biocompatible polymer [poly(lactide-co-glycolide), PLG] and be released in quantities that inhibit the formation of Pseudomonas aeruginosa biofilms by up to 75–90% on surfaces t...

  7. 血清抗b型流感嗜血杆菌磷酸多聚核糖基核糖醇抗体杀菌活性体外检测方法的建立%Development of Serum Bactericidal Assay In Vitro for Determination of Bactericidal Activity of Serum Anti-Haemophilus influenzae Type b Polyribosylribitol Phosphate Antibody

    Institute of Scientific and Technical Information of China (English)

    乔瑞洁; 李亚南; 赵志强; 刘佳; 王浩; 史晓玲; 谭小梅; 杜送田; 谢贵林

    2011-01-01

    Objective To develop a serum bactericidal assay(SBA) in vitro for determination of bactericidal activity of serum anti-Haemophilus infiuenzae type b (Hib) polyribosylribitol phosphate (PRP) antibody. Methods A SBA method was developed by screening of complement and index bacterial strain, and verified for stability, specificity and precision. Results Hib-EAGAN strain as an index strain and Hib-pesitive serum showed high bactericidal specificity, of bath of which the non-specific bactericidal rates were 0. of the four batches of complements provided by Pel-Freez, Lot 17830 showed high stability and specificity. The result of verification showed high stability and specificity of the developed Hib-SBA system, of which the CV of precision was 16% ~ 28%. Conclusion The SBA in vitro for determination of bactericidal activity of serum anti-Hib-PRP was successfully developed, which was of high-throughput, was time-saving and easy to be standardized.%目的 建立免疫血清中抗b型流感嗜血杆菌(Haemophilus influenzae type b,Hib)磷酸多聚核糖基核糖醇(Polyribosylribitol phosphate,PRP)抗体体外血清杀菌试验(Serum bacterialcid assay,SBA)方法.方法 通过对补体和指示菌株的筛选,建立体外测定血清中抗Hib-PRP抗体杀菌试验方法,并对实验体系的耐变性、特异性及精密性进行验证.结果 指示菌Hib-EAGAN株与Hib阳性血清显示出良好的杀菌特异性,其平均非特异性杀菌率为0;Pel-Freez公司提供的4批补体中,批号为17830的补体具有良好的杀菌稳定性和特异性;经验证,建立的Hib-SBA体系具有良好的耐变性和特异性,其精密性CV值在16%~28%之间.结论 成功建立了血清抗Hib-PRP抗体杀菌活性体外检测方法,该方法具有检测样本量大、省时、易标准化等优点.

  8. Antimicrobial activity of human α-defensin 6 analogs: insights into the physico-chemical reasons behind weak bactericidal activity of HD6 in vitro.

    Science.gov (United States)

    Mathew, Basil; Nagaraj, Ramakrishnan

    2015-11-01

    Human α-defensin 6 (HD6), unlike other mammalian defensins, does not exhibit bactericidal activity, particularly against aerobic bacteria. Monomeric HD6 has a tertiary structure similar to other α-defensins in the crystalline state. However, the physico-chemical reasons behind the lack of antibacterial activity of HD6 are yet to be established unequivocally. In this study, we have investigated the antimicrobial activity of HD6 analogs. A linear analog of HD6, in which the distribution of arginine residues was similar to active α-defensins, shows broad-spectrum antimicrobial activity, indicating that atypical distribution of arginine residues contributes to the inactivity of HD6. Peptides spanning the N-terminal cationic segment were active against a wide range of organisms. Antimicrobial potency of these shorter analogs was further enhanced when myristic acid was conjugated at the N-terminus. Cytoplasmic localization of the analogs without fatty acylation was observed to be necessary for bacterial killing, while they exhibited fungicidal activity by permeabilizing Candida albicans membranes. Myristoylated analogs and the linear full-length arginine analog exhibited activity by permeabilizing bacterial and fungal membranes. Our study provides insights into the lack of bactericidal activity of HD6 against aerobic bacteria. PMID:26400692

  9. Bactericidal activity and mechanism of AgI/AgBr/BiOBr(0.75)I(0.25) under visible light irradiation.

    Science.gov (United States)

    Liang, Jialiang; Deng, Jun; Li, Mian; Tong, Meiping

    2016-02-01

    The AgI/AgBr/BiOBr0.75I0.25 nanocomposites were synthesized by a solvothermal process, followed by an in-situ ion exchange reaction. The disinfection activities of the as-synthesized photocatalyst to model cell type, Gram-negative Escherichia coli (E. coli), were investigated under visible light irradiation condition (λ≥400 nm). Results showed that 80 mg/L AgI/AgBr/BiOBr0.75I0.25 could completely inactivate 3×10(7) CFU mL(-1)E. coli cells within 30 min under visible light irradiation. Moreover, the bactericidal mechanisms involved in the photocatalytic disinfection process were systematically investigated. Ag(+) ions released from the nanocomposites negligibly contributed to the bactericidal activity, while active species including h(+), e(-) and ·O2(-) played important roles in the disinfection system. Direct contact of bacterial cells and nanoparticles was found to be the prerequisite for both the generation of ·O2(-) and the disinfection processes. The disruption of cell membrane and emission of cytoplasm directly inactivated E. coli cells. In addition, AgI/AgBr/BiOBr0.75I0.25 exhibited strong antibacterial activity toward E. coli even in four consecutive reused cycles. PMID:26674838

  10. Spectroscopy investigation on chemo-catalytic, free radical scavenging and bactericidal properties of biogenic silver nanoparticles synthesized using Salicornia brachiata aqueous extract

    Science.gov (United States)

    Seralathan, Janani; Stevenson, Priscilla; Subramaniam, Shankar; Raghavan, Rachana; Pemaiah, Brindha; Sivasubramanian, Aravind; Veerappan, Anbazhagan

    2014-01-01

    Nanosized silver have been widely used in many applications, such as catalysis, photonics, sensors, medicine etc. Thus, there is an increasing need to develop high-yield, low cost, non-toxic and eco-friendly procedures for the synthesis of nanoparticles. Herein, we report an efficient, green synthesis of silver nanoparticles utilizing the aqueous extract of Salicornia brachiata, a tropical plant of the Chenopodiaceae family. Silver nanoparticles have been characterized by ultraviolet-visible spectroscopy, scanning electron microscopy and transmission electron microscopy. The morphology of the particles formed consists of highly diversified shapes like spherical, rod-like, prism, triangular, pentagonal and hexagonal pattern. However, addition of sodium hydroxide to the extract produces mostly spherical particles. The stable nanoparticles obtained using this green method show remarkable catalytic activity in the reduction of 4-nitro phenol to 4-amino phenol. The reduction catalyzed by silver nanoparticles followed the first-order kinetics, with a rate constant of, 0.6 × 10-2 s-1. The bactericidal activity of the synthesized silver nanoparticles against the pathogenic bacteria, Staphylococcus aureus, Staphylococcus aureus E, Bacillus subtilis and Escherichia coli, was also explored using REMA. The obtained results showed that the minimum inhibitory concentration required to induce bactericidal effect is lower than the control antibiotic, ciprofloxacin. In addition to these, the biogenic synthesized nanoparticles also exhibited excellent free radical scavenging activity.

  11. Influence of the surface properties on bactericidal and fungicidal activity of magnetron sputtered Ti-Ag and Nb-Ag thin films.

    Science.gov (United States)

    Wojcieszak, D; Mazur, M; Kaczmarek, D; Mazur, P; Szponar, B; Domaradzki, J; Kepinski, L

    2016-05-01

    In this study the comparative investigations of structural, surface and bactericidal properties of Ti-Ag and Nb-Ag thin films have been carried out. Ti-Ag and Nb-Ag coatings were deposited on silicon and fused silica substrates by magnetron co-sputtering method using innovative multi-target apparatus. The physicochemical properties of prepared thin films were examined with the aid of X-ray diffraction, grazing incidence X-ray diffraction, scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy methods. Moreover, the wettability of the surface was determined. It was found that both, Ti-Ag and Nb-Ag thin films were nanocrystalline. In the case of Ag-Ti film presence of AgTi3 and Ag phases was identified, while in the structure of Nb-Ag only silver occurred in a crystal form. In both cases the average size of crystallites was ca. 11nm. Moreover, according to scanning electron microscopy and atomic force microscopy investigations the surface of Nb-Ag thin films was covered with Ag-agglomerates, while Ti-Ag surface was smooth and devoid of silver particles. Studies of biological activity of deposited coatings in contact with Bacillus subtilis, Pseudomonas aeruginosa, Enterococcus hirae, Klebisiella pneumoniae, Escherichia coli, Staphylococcus aureus and Candida albicans were performed. It was found that prepared coatings were bactericidal and fungicidal even in a short term-contact, i.e. after 2h. PMID:26952401

  12. Bactericidal activity of juvenile chinook salmon macrophages against Aeromonas salmonicida after exposure to live or heat-killed Renibacterium salmoninarum or to soluble proteins produced by R. salmoninarum

    Science.gov (United States)

    Siegel, D.C.; Congleton, J.L.

    1997-01-01

    Macrophages isolated from the anterior kidney of juvenile chinook salmon Oncorhynchus tshawytscha in 96-well microtiter plates were exposed for 72 h to 0, 105, or 106 live or heat-killed Renibacterium salmoninarum cells per well or to 0, 0.1, 1.0, or 10 ??g/mL of R. salmoninarum soluble proteins. After treatment, the bactericidal activity of the macrophages against Aerornonas salmonicida was determined by a colorimetric assay based on the reduction of the tetrazolium dye MTT to formazan by viable bacteria. The MTT assay was modified to allow estimation of the percentage of bacteria killed by reference to a standard curve relating the number of bacteria added to microtiter wells to absorbance by formazan at 600 nm. The live and heat-killed R. salmoninarum treatments significantly (P < 0.001) increased killing of A. salmonicida by chinook salmon macrophages. In each of the five trials, significantly (P < 0.05) greater increases in killing occurred after exposure to 105 R. salmoninarum cells than to 106 R. salmoninarum cells per well. In contrast, treatment of macrophages with 10 ??g/mL R. salmoninarum soluble proteins significantly (P < 0.001) decreased killing of A. salmonicida, but treatment with lower doses did not. These results show that the bactericidal activity of chinook salmon macrophages is stimulated by exposure to R. salmoninarum cells at lower dose levels but inhibited by exposure to R. salmoninarum cells or soluble proteins at higher dose levels.

  13. Synergistic bactericidal action of phytic acid and sodium chloride against Escherichia coli O157:H7 cells protected by a biofilm.

    Science.gov (United States)

    Kim, Nam Hee; Rhee, Min Suk

    2016-06-16

    The food industry must prevent the build-up of strong Escherichia coli O157:H7 biofilms in food processing environments. The present study examined the bactericidal action of phytic acid (PA), a natural extract from rice bran and the hulls/peels of legumes, against E. coli O157:H7 biofilms. The synergistic bactericidal effects of PA plus sodium chloride (NaCl) were also examined. E. coli O157:H7 biofilms were allowed for form on stainless steel coupons by culture in both rich (tryptic soy broth, TSB) and minimal (M9) medium at 22°C for 6days. Bacterial cells within biofilms grown in M9 medium were significantly more resistant to PA than those grown in TSB (p6.5logCFU/cm(2) reduction). Neither PA nor NaCl alone were this effective (PA, 1.6-2.7logCFU/cm(2) reduction; NaCl, <0.5logCFU/cm(2) reduction). Confocal laser scanning microscopy images of propidium iodide-treated cells showed that PA (0.4%) plus NaCl (2-4%) had marked membrane permeabilizing effects. These results suggest that a sanitizer that combines these two naturally occurring antimicrobial agents may be useful to food safety managers who encounter thick biofilm formation in food processing environments. PMID:27043385

  14. 打瓜白粉病药剂防治技术研究%Study on the Technique of Controling Seed- used Watermelon Powdery Mildew with Bactericides

    Institute of Scientific and Technical Information of China (English)

    韩盛; 李新辉; 于建新; 王艳; 杨渡; 李承业; 潘竟海; 李妍娥; 杨静飞; 严丽; 刘同业; 侯秀芳

    2012-01-01

    [ Objective ] Because seed - used watermelon powdery mildew induced serious damage in Xinjiang Region, we study the control efficacy of six bactericides to seed - used watermelon powdery mildew in the field. [Method] Comparison of the control efficacy of six bactericides to seed -used watermelon powdery mildew was made in the field plot experiment. [Result]Fourteen days after using these bactericides twice, thecontrol efficacy of 10% ZJ0712 wp 5 ,000 times solution is 73. 80% , achieving the highest control efficacy in all the six used bactericides And the control efficacy of 10% ZJ0712 wp 1,0000 times solution, 50% Kresoxim - methyl WG 3 ,000 times solution, 400 g/L Flusilazole EC 7 ,500 times solution and 25% Ethirimol wp 1,500 times solution are also effective, reaching the effect of 69. 69% , 69.56% , 68. 48% , and 67. 32% respectively after being used 14 days later. [ Conclusion]The control efficacy of ZJ0712 wp, 50% Kresoxim - methyl WG, 400 g/L Flusilazole EC and 25% Ethirimol wp are quite effective, so it is suggested that they could be used in production by turn, and the rule for controlling seed - used watermelon powdery mildew is made. The primary sources of infection and suitable time for controlling this disease have been clearly made, too. The key to controlling seed - used watermelon powdery mildew is to spray effective bactericide in time.%[目的]针对打瓜白粉病在新疆严重危害的现状,研究6种杀菌剂对打瓜白粉病的田间防治效果.[方法]采用田间小区试验,比较6种药剂的防效差异.[结果]两次施药后第14 d,10%苯醚菌酯悬浮剂5000倍液防效最高,防效达73.80%.10%苯醚菌酯悬浮剂10 000倍液、50%醚菌酯水分散粒剂3 000倍液、400 g/L氟硅唑乳油7 500倍液和25%乙嘧酚悬浮剂1 500倍液的防效也较好,药后14 d分别达69.69%、69.56%、68.48%和67.32%.[结论]4种药剂防效较好,推荐在生产中交替使用.提出了打瓜白粉病防治原则,明

  15. Oral Immunization of Rabbits with S. enterica Typhimurium Expressing Neisseria gonorrhoeae Filamentous Phage Φ6 Induces Bactericidal Antibodies Against N. gonorrhoeae.

    Science.gov (United States)

    Piekarowicz, Andrzej; Kłyż, Aneta; Majchrzak, Michał; Stein, Daniel C

    2016-01-01

    All Neisseria gonorrhoeae strains whose DNA sequences have been determined possess filamentous phage DNA sequences. To ascertain if phage encoded proteins could form the basis of a gonococcal vaccine, rabbits were orally infected with S. enterica Typhimurium strain χ3987 harboring phagemid NgoΦ6 fm. The elicited sera contained large quantities of anti-phage IgG and IgA antibodies that bound to the surface of N. gonorrhoeae cells, as shown by indirect fluorescent analysis and flow cytometry. The elicited sera was able to bind to several phage proteins. The sera also had bactericidal activity. These data demonstrate that N. gonorrhoeae filamentous phage can induce antibodies with anti-gonococcal activity and that phage proteins may be a candidate for vaccine development. PMID:26939573

  16. Children with Haemophilus influenzae type b (Hib) vaccine failure have long-term bactericidal antibodies against virulent Hib strains with multiple capsular loci.

    Science.gov (United States)

    Townsend-Payne, Kelly; Ladhani, Shamez N; Findlow, Helen; Slack, Mary; Borrow, Ray

    2016-07-25

    Children who develop invasive Haemophilus influenzae serotype b (Hib) disease after immunisation with a highly-effective conjugate vaccine are more likely to have been infected with Hib strains possessing multiple copies of the capsulation locus. Using a recently-validated serum bactericidal antibody (SBA) assay, we tested convalescent sera from 127 Hib vaccine failure cases against clinical Hib strains expressing 1-5 copies of the capsulation locus. SBA titres correlated weakly with anti-capsular IgG antibody concentrations and there was no association between SBA geometric mean titres and number of capsulation locus copies. After infection, children with Hib vaccine failure were equally protected against Hib strains with 1-5 copies of the capsulation locus. PMID:27317452

  17. Microbial and chemical origins of the bactericidal activity of thermally treated yellow mustard powder toward Escherichia coli O157:H7 during dry sausage ripening.

    Science.gov (United States)

    Luciano, Fernando B; Belland, Julie; Holley, Richard A

    2011-01-31

    Work examines the origin of bactericidal activity in mustard flour and explores the relative contribution from starter cultures, E. coli O157:H7 itself and other sources. Bacteria can degrade naturally occurring glucosinolates in mustard and form isothiocyanates with antimicrobial activity. In the present work, 24 starter cultures (mostly from commercial mixtures) were screened for their capacity to decompose the glucosinolate, sinalbin. The most active pair, Pediococcus pentosaceus UM 121P and Staphylococcus carnosus UM 123 M, were used together for the production of dry fermented sausage contaminated with E. coli O157:H7 (~6.5 log CFU/g). They were compared to industrial starters used previously (P. pentosaceus UM 116P and S. carnosus UM 109 M) for their reduction of E. coli O157:H7 viability. Sausage batches containing hot mustard powder (active myrosinase), cold mustard powder (inactivated myrosinase), autoclaved mustard powder (inactivated myrosinase) and no mustard flour (control) were prepared. Interestingly, both pairs of starter cultures yielded similar results. Elimination of E. coli O157:H7 (>5 log CFU/g) occurred after 31 days in the presence of hot flour and in 38 days when the cold flour was added. Reductions >5 log CFU/g of the pathogen did not occur (up to 38 days) in the control group. It was found that E. coli O157:H7 itself had a greater effect on sinalbin conversion than either pair of starter cultures, and glucosinolate degradation by the starter cultures was less important in determining E. coli survival. The autoclaved powder caused more rapid bactericidal action against E. coli O157:H7, yielding a >5 log CFU/g reduction in 18 days. This may have been a result of the formation and/or release of antimicrobial substances by the autoclave treatment. Autoclaved mustard powder could potentially solve an important challenge facing the meat industry as it strives to manufacture safe dry fermented sausages. PMID:21146240

  18. Efeito bactericida do gerador de alta frequência na cultura de Staphylococcus aureus Bactericidal effect of high frequency generator in Staphylococcus aureus culture

    Directory of Open Access Journals (Sweden)

    Andiara Martins

    2012-06-01

    Full Text Available O objetivo deste estudo foi verificar o efeito bactericida do gerador de alta frequência sobre a cultura de Staphylococcus aureus. Para isso, 36 placas de Petri inoculadas com Staphylococcus aureus foram divididas em 6 grupos, sendo 4 tratados (G5-15, G5-10, G3-15 e G3-10 e 2 controles (GC3 e GC5. O G5-15 e o G5-10 foram tratados 5 vezes por semana durante 15 e 10 minutos respectivamente, enquanto o G3-15 e o G3-10 foram tratados 3 vezes por semana durante 15 e 10 minutos respectivamente. No tratamento, foi utilizado o gerador de alta frequência na intensidade 10, técnica de faiscamento com eletrodo standard. Após o 15º dia de tratamento, foram realizadas repicagens para verificar se houve crescimento de novas culturas, observando-se que apenas o G5-15 mostrou-se eficaz quando comparado ao GC5 (p=0,0039. Assim, o gerador de alta frequência apresentou efeito bactericida diante de cultura de Staphylococcus aureus in vitro em uma frequência de 5 vezes por semana aplicado por 15 minutos diários.The purpose of this study was to check the bactericidal effect of the high frequency generator over the Staphylococcus aureus culture. A total of 36 Petri dishes inoculated with Staphylococcus aureus were divided into 6 groups, including 4 treated (G5-15, G5-10, G3-15 and G3-10 and 2 controls (GC3 e GC5. G5-15 and G5-10 were treated 5 times per week during 15 and 10 minutes, respectively, while G3-15 and G3-10 were treated 3 times per week during 15 and 10 minutes, respectively. In treatment, it was used the high frequency generator with intensity of 10, sparking technique with standard electrode. After the 15th day of treatment, there were performed transplanting, in order to check if there were growth of new cultures, and only G5-15 showed to be effective when compared to GC5 (p=0.0039. So, the high frequency generator had a bactericidal effect on Staphylococcus aureus in vitro culture at a frequency of 5 times per week and exposure time of 15

  19. Preparation of Ag/TiO{sub 2}/SiO{sub 2} films via photo-assisted deposition and adsorptive self-assembly for catalytic bactericidal application

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Baojuan, E-mail: baojuanxi@gmail.com [Department of Electrical and Computer Engineering, 10 Kent Ridge Crescent, Singapore 119260 (Singapore); Chu, Xiaona; Hu, Jiangyong [Department of Civil and Environmental Engineering, 10 Kent Ridge Crescent, Singapore 119260 (Singapore); Bhatia, Charanjit Singh; Danner, Aaron James; Yang, Hyunsoo [Department of Electrical and Computer Engineering, 10 Kent Ridge Crescent, Singapore 119260 (Singapore)

    2014-08-30

    Highlights: • We prepared controlledly the silver nanoparticles on TiO{sub 2}/SiO{sub 2} film by the facile photoreduction under the aid of structure-directing agents. • We studied the effect of silver loading on the antibactierial behavior of TiO{sub 2} film and optimized the content of silver. • We extended the route to fabricate other metals on substrates. - Abstract: The deterioration of water supply quality due to the waterborne bacteria is an environmental problem requiring the urgent attention. Due to the excellent and synergic antimicrobial capability, Ag-loaded TiO{sub 2} photocatalyst emerges as a feasible measure to guard the water. In our work, Ag nanoparticles have been prepared by the photoassisted reduction of AgNO{sub 3} on the TiO{sub 2} film fabricated by solution-based adsorptive self-assembly approach. The role of surfactant on the growth rate and size controlling of particles is also studied. In this connection, different kinds of surfactants, such as PVP, Tween-20, Tween-40 and so on, are applied in the system to investigate the formation of Ag nanoparticles. The surface profile and elemental analysis of Ag/TiO{sub 2}/SiO{sub 2} films are examined by scanning electron microscopy and attached energy-dispersive X-ray spectroscopy, respectively. In the anti-bacteria detection, Ag nanoparticles are found to enhance the bactericidal efficiency strongly comparing with the pure TiO{sub 2} film under the same condition. In addition, by comparison with Ag/TiO{sub 2}/SiO{sub 2} film in the dark environment as the reference experiment, UV–visible light plays a vital role in the improved bactericidal behavior, demonstrating the more efficient charge separation induced by metal silver. Because of the versatility of the method, the present photoreductive route is also exploited for the synthesis of Au nanoparticles on TiO{sub 2}/SiO{sub 2} films. The corresponding photocatalytical detection results demonstrate the loading of Au nanoparticles can

  20. Preparation of Ag/TiO2/SiO2 films via photo-assisted deposition and adsorptive self-assembly for catalytic bactericidal application

    International Nuclear Information System (INIS)

    Highlights: • We prepared controlledly the silver nanoparticles on TiO2/SiO2 film by the facile photoreduction under the aid of structure-directing agents. • We studied the effect of silver loading on the antibactierial behavior of TiO2 film and optimized the content of silver. • We extended the route to fabricate other metals on substrates. - Abstract: The deterioration of water supply quality due to the waterborne bacteria is an environmental problem requiring the urgent attention. Due to the excellent and synergic antimicrobial capability, Ag-loaded TiO2 photocatalyst emerges as a feasible measure to guard the water. In our work, Ag nanoparticles have been prepared by the photoassisted reduction of AgNO3 on the TiO2 film fabricated by solution-based adsorptive self-assembly approach. The role of surfactant on the growth rate and size controlling of particles is also studied. In this connection, different kinds of surfactants, such as PVP, Tween-20, Tween-40 and so on, are applied in the system to investigate the formation of Ag nanoparticles. The surface profile and elemental analysis of Ag/TiO2/SiO2 films are examined by scanning electron microscopy and attached energy-dispersive X-ray spectroscopy, respectively. In the anti-bacteria detection, Ag nanoparticles are found to enhance the bactericidal efficiency strongly comparing with the pure TiO2 film under the same condition. In addition, by comparison with Ag/TiO2/SiO2 film in the dark environment as the reference experiment, UV–visible light plays a vital role in the improved bactericidal behavior, demonstrating the more efficient charge separation induced by metal silver. Because of the versatility of the method, the present photoreductive route is also exploited for the synthesis of Au nanoparticles on TiO2/SiO2 films. The corresponding photocatalytical detection results demonstrate the loading of Au nanoparticles can improve the photodegradation efficiency of methyl orange assigned to the similar

  1. The meningococcal transferrin-binding proteins 1 and 2 are both surface exposed and generate bactericidal antibodies capable of killing homologous and heterologous strains.

    Science.gov (United States)

    Ala'Aldeen, D A; Borriello, S P

    1996-01-01

    When grown in vivo, or under iron-restriction in vitro, Neisseria meningitidis expresses a number of iron-regulated outer membrane proteins, including two transferrin-binding proteins (Tbp1 and Tbp2). The Tbps are highly specific receptors for human transferrin and we have previously demonstrated their immunogenicity in humans and animals and their exposure on the surface of the organism. There is a growing interest in incorporating these Tbps in future outer membrane-based meningococcal vaccines. Protection against meningococcal infection has been correlated with serum bactericidal antibodies, therefore, it is important for these vaccine candidates to generate such antibodies. We have previously raised rabbit and murine polyclonal monospecific antisera against the Tbps of strain SD (B:15:P1.16) which showed varying degrees of cross-reactivity on immunoblots between the Tbp1 and/or Tbp2 molecules of different heterologous strains from various serogroups, types and subtypes. The ability of these antisera to kill meningococci were tested by incubating live organisms (grown to log phase under iron-restriction) with the antisera in the presence of a human complement source (serum from an agammaglobulinaemic patient). The antisera killed the homologous and the majority of the examined heterologous strains with varying efficiency, with no obvious correlation with the identity of the strains or the Tbp isotypes which vary between strains. Although the animal anti-Tbp antibodies failed to kill some meningococcal strains, it is not clear how human anti-Tbp antibodies would behave. The mouse antiserum was able to kill some heterologous stains against which it only had detectable anti-Tbp1 and not anti-Tbp2 antibodies, as seen on Western blots. Furthermore, the rabbit antiserum was able to kill both Tbp1 and Tbp2 mutants of strain B16B6 (B2a:P1.2) to almost the same level as the wild type strain, indicating that both components of the transferrin receptor (Tbp1 and Tbp2) are

  2. Eco-friendly synthesis of silver and gold nanoparticles with enhanced bactericidal activity and study of silver catalyzed reduction of 4-nitrophenol

    Science.gov (United States)

    Naraginti, Saraschandra; Sivakumar, A.

    2014-07-01

    The present study reports a simple and robust method for synthesis of silver and gold nanoparticles using Coleus forskohlii root extract as reducing and stabilizing agent. Stable silver nanoparticles (AgNPs) and gold nanopoarticles (AuNPs) were formed on treatment of an aqueous silver nitrate (AgNO3) and chloroauric acid (HAuCl4) solutions with the root extract. The nanoparticles obtained were characterized by UV-Visible spectroscopy, Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). UV-Vis and TEM analysis indicate that with higher quantities of root extract, the interaction is enhanced leading to size reduction of spherical metal nanoparticles. XRD confirms face-centered cubic phase and the diffraction peaks can be attributed to (1 1 1), (2 0 0), (2 2 2) and (3 1 1) planes for these nanoparticles. These synthesized Ag and Au nanoparticles were found to exhibit excellent bactericidal activity against clinically isolated selected pathogens such as Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus). The synthesized AgNPs were also found to function as an efficient green catalyst in the reduction of anthropogenic pollutant 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by sodium borohydride, which was apparent from the periodical color change from bright yellow to colorless, after the addition of AgNPs.

  3. Characterization and relative photonic efficiencies of a new nanocarbon/TiO2 composite photocatalyst designed for organic dye decomposition and bactericidal activity

    International Nuclear Information System (INIS)

    Two kinds of nanocarbon/TiO2 composite photocatalysts were synthesized using an MCPBA oxidation method, employing MWCNT (multi-wall carbon nanotubes) and C60 as nanocarbon sources and TNB (titanium (IV) n-butoxide) as a titanium dioxide source. From the XRD patterns of the composites, structural variations revealed the C60/TiO2 composite having a mixture of anatase and rutile forms, with the MWCNT/TiO2 composite presenting only the anatase phase. Elemental analysis indicated a predominance of carbon and Ti metal peaks over any other element. From the SEM results, the TiO2 particles were dispersed regularly on the fullerene surface with large clusters bearing irregular agglomerate dispersions. However, the MWCNT/TiO2 showed homogenous distributions with only individual MWCNT, covered with TiO2 and without any jam-like aggregates between the two. According to the photocatalytic results, the relationship of the -ln (c/c0) of the solution products of the organic dye, methylene blue (MB), as a function of time under UV irradiation, showed linearity properties with first-order kinetics and an excellent photodegradation effect. From the measured bactericidal effects, the inhibition zone was defined by the halo method with the curves of E. coli inactivation denoting effectiveness of the nanocarbon/TiO2 composites in the sunlight.

  4. Design, synthesis and in vitro bactericidal/fungicidal screening of some vanadyl(IV)complexes with mono- and di-substituted ONS donor triazoles.

    Science.gov (United States)

    Sumrra, Sajjad H; Hanif, Muhammad; Chohan, Zahid H

    2015-01-01

    A new series of anti-bacterial and anti-fungal mono- and di-substituted triazoles (L(1))-(L(6)) have been synthesized and characterized on the basis of their physical, spectral and analytical data. The ligands (L(1))-(L(6)) on reaction with vanadyl(IV) sulphate led to the formation of vanadyl(IV) metal complexes (1)-(4). The structure of the complexes has been established on the basis of their physical, spectral and elemental analyses data. The synthesized ligands and their vanadyl(IV) complexes have been screened in vitro for anti-bacterial activity against six bacterial species such as, Escherichia coli (ATCC 25922), Shigella flexneri (ATCC 12022), Pseudomonas aeruginosa (ATCC 27853), Salmonella typhi (ATCC 14028), Staphylococcus aureus (ATCC 25923) and Bacillus subtilis (ATCC 6051) and for in vitro anti-fungal activity against six fungal strains, Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glabrata. The screening results showed the vanadyl complexes to be more bactericidal/fungicidal against one or more bacterial/fungal species. The synthesized compounds were also subjected to brine shrimp bioassay for scrutinizing their cytotoxicity. PMID:25716124

  5. Bactericidal Mechanism of Bio-oil Obtained from Fast Pyrolysis of Pinus densiflora Against Two Foodborne Pathogens, Bacillus cereus and Listeria monocytogenes.

    Science.gov (United States)

    Patra, Jayanta Kumar; Hwang, Hyewon; Choi, Joon Weon; Baek, Kwang-Hyun

    2015-06-01

    Foodborne bacteria are the leading cause of food spoilage and other related diseases. In the present study, the antibacterial activity of bio-oil (BO) manufactured by fast pyrolysis of pinewood sawdust (Pinus densiflora Siebold and Zucc.) against two disease-causing foodborne pathogens (Bacillus cereus and Listeria monocytogenes) was evaluated. BO at a concentration of 1000 μg/disc was highly active against both B. cereus (10.0-10.6 mm-inhibition zone) and L. monocytogenes (10.6-12.0-mm inhibition zone). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration values of BO were 500 and 1000 μg/mL, respectively, for both pathogens. At the MIC concentration, BO exhibited an inhibitory effect on the viability of the bacterial pathogens. The mechanism of action of BO revealed its strong impairing effect on the membrane integrity of bacterial cells, which was confirmed by a marked release of 260-nm absorbing material, leakage of electrolytes and K(+) ions, and reduced capacity for osmoregulation under high salt concentration. Scanning electron microscopy clearly showed morphological alteration of the cell membrane due to the effect of BO. Overall, the results of this study suggest that BO exerts effective antibacterial potential against foodborne pathogens and can therefore potentially be used in food processing and preservation. PMID:25928035

  6. Aqueous and Organic Solvent-Extracts of Selected South African Medicinal Plants Possess Antimicrobial Activity against Drug-Resistant Strains of Helicobacter pylori: Inhibitory and Bactericidal Potential

    Directory of Open Access Journals (Sweden)

    Collise Njume

    2011-09-01

    Full Text Available The aim of this study was to identify sources of cheap starting materials for the synthesis of new drugs against Helicobacter pylori. Solvent-extracts of selected medicinal plants; Combretum molle, Sclerocarya birrea, Garcinia kola, Alepidea amatymbica and a single Strychnos species were investigated against 30 clinical strains of H. pylori alongside a reference control strain (NCTC 11638 using standard microbiological techniques. Metronidazole and amoxicillin were included in these experiments as positive control antibiotics. All the plants demonstrated anti-H. pylori activity with zone diameters of inhibition between 0 and 38 mm and 50% minimum inhibitory concentration (MIC50 values ranging from 0.06 to 5.0 mg/mL. MIC50 values for amoxicillin and metronidazole ranged from 0.001 to 0.63 mg/mL and 0.004 to 5.0 mg/mL respectively. The acetone extracts of C. molle and S. birrea exhibited a remarkable bactericidal activity against H. pylori killing more than 50% of the strains within 18 h at 4× MIC and complete elimination of the organisms within 24 h. Their antimicrobial activity was comparable to the control antibiotics. However, the activity of the ethanol extract of G. kola was lower than amoxicillin (P < 0.05 as opposed to metronidazole (P > 0.05. These results demonstrate that S. birrea, C. molle and G. kola may represent good sources of compounds with anti-H. pylori activity.

  7. Exploring a new phenomenon in the bactericidal response of TiO{sub 2} thin films by Fe doping: Exerting the antimicrobial activity even after stoppage of illumination

    Energy Technology Data Exchange (ETDEWEB)

    Naghibi, Sanaz, E-mail: naghibi@iaush.ac.ir [Department of Metallurgy and Materials Engineering, Shahreza Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of); Vahed, Shohreh, E-mail: sh_vahed@iaush.ac.ir [Department of Food Science, Shahreza Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of); Torabi, Omid, E-mail: omid_trb@yahoo.com [Department of Materials Engineering, Najafabad Branch, Advanced Materials Research Center, Islamic Azad University, Isfahan (Iran, Islamic Republic of); Jamshidi, Amin, E-mail: amin_jam_g@yahoo.com [Department of Materials Engineering, Najafabad Branch, Advanced Materials Research Center, Islamic Azad University, Isfahan (Iran, Islamic Republic of); Golabgir, Mohammad Hossein, E-mail: m.hosseingolabgir@yahoo.com [Department of Materials Engineering, Najafabad Branch, Advanced Materials Research Center, Islamic Azad University, Isfahan (Iran, Islamic Republic of)

    2015-02-01

    Graphical abstract: - Highlights: • Highly uniform Fe–TiO{sub 2} thin films were deposited on glass using sol–gel hot-dipping technique. • The photocatalytic properties were studied upon UV and visible irradiation. • By Fe doping into TiO{sub 2} structure, its microbial performance was prolonged even after stopping the illumination. • Due to Fe doping, the significant improvement in bactericidal coating was evident. - Abstract: Antibacterial properties of Fe-doped TiO{sub 2} thin films prepared on glass by the sol–gel hot-dipping technique were studied. The films were characterized by X-ray diffraction, field emission scanning electron microscopy, scanning probe microscopy and X-ray photoelectron spectroscopy. The photocatalytic activities were evaluated by measuring the decomposition rate of methylene blue under ultra violet and visible light. The antibacterial properties of the coatings were investigated against Escherichia coli, Staphylococcus aureus, Saccharomyces cerevisia and Aspergillus niger. The principle of incubation methods was also discussed. The results indicated that Fe doping of thin films eventuated in high antibacterial properties under visible light and this performance remained even after stoppage of illumination. This article tries to provide some explanation for this fact.

  8. Evaluation of the bactericidal characteristics of nano-copper oxide or functionalized zeolite coating for bio-corrosion control in concrete sewer pipes

    International Nuclear Information System (INIS)

    The bactericidal characteristics of nano-copper oxide or functionalized zeolite coated concrete pipes against Acidithiobacillus thiooxidans were studied by measuring the temporal variation of bacterial dry cell weight measurement, cellular Adenosine Triphosphate production, as well as oxygen uptake rate of the aforementioned bacterium. Uncorroded (UC), severely corroded (SC), and moderately corroded (MC) concrete pipes were electrochemically coated with a nano-copper oxide, while another uncorroded concrete pipe was used to apply functionalized zeolite coating (Z2). Specimens were characterized by field emission-scanning electron microscopy, and optical microscopy. Oxygen uptake rate of the bacterium was the highest in UC followed by the MC. Oxygen uptake rate and cellular Adenosine Triphosphate decreased progressively in Z2 and SC throughout the duration of the experiment due to decline in live bacterial cell. The maximum bacterial specific growth rate was 1.1 x 10-2 day-1 for both UC and MC, with a decay rates varying from 1.4 x 10-2 to 2.6 x 10-2 day-1. The minimum concentration limits for the inhibition of the bacterium in the nano-copper oxide coated concrete pipes ranged from 2.3 mg to 2.6 mg Cu per mg dry cell weight.

  9. Stem Bark Extract and Fraction of Persea americana (Mill. Exhibits Bactericidal Activities against Strains of Bacillus cereus Associated with Food Poisoning

    Directory of Open Access Journals (Sweden)

    David A. Akinpelu

    2014-12-01

    Full Text Available The study investigates the in vitro antibacterial potentials of stem bark extracts of Persea americana on strains of Bacillus cereus implicated in food poisoning. The crude stem bark extracts and butanolic fraction at a concentration of 25 mg/mL and 10 mg/mL, respectively, exhibited antibacterial activities against test isolates. The zones of inhibition exhibited by the crude extract and the fraction ranged between 10 mm and 26 mm, while the minimum inhibitory concentration values ranged between 0.78 and 5.00 mg/mL. The minimum bactericidal concentrations ranged between 3.12 mg/mL–12.5 mg/mL and 1.25–10 mg/mL for the extract and the fraction, respectively. The butanolic fraction killed 91.49% of the test isolates at a concentration of 2× MIC after 60 min of contact time, while a 100% killing was achieved after the test bacterial cells were exposed to the butanolic fraction at a concentration of 3× MIC after 90 min contact time. Intracellular protein and potassium ion leaked out of the test bacterial cells when exposed to certain concentrations of the fraction; this is an indication of bacterial cell wall disruptions by the extract’s butanolic fraction and, thus, caused a biocidal effect on the cells, as evident in the killing rate test results.

  10. Stem bark extract and fraction of Persea americana (Mill.) exhibits bactericidal activities against strains of bacillus cereus associated with food poisoning.

    Science.gov (United States)

    Akinpelu, David A; Aiyegoro, Olayinka A; Akinpelu, Oluseun F; Okoh, Anthony I

    2015-01-01

    The study investigates the in vitro antibacterial potentials of stem bark extracts of Persea americana on strains of Bacillus cereus implicated in food poisoning. The crude stem bark extracts and butanolic fraction at a concentration of 25 mg/mL and 10 mg/mL, respectively, exhibited antibacterial activities against test isolates. The zones of inhibition exhibited by the crude extract and the fraction ranged between 10 mm and 26 mm, while the minimum inhibitory concentration values ranged between 0.78 and 5.00 mg/mL. The minimum bactericidal concentrations ranged between 3.12 mg/mL-12.5 mg/mL and 1.25-10 mg/mL for the extract and the fraction, respectively. The butanolic fraction killed 91.49% of the test isolates at a concentration of 2× MIC after 60 min of contact time, while a 100% killing was achieved after the test bacterial cells were exposed to the butanolic fraction at a concentration of 3× MIC after 90 min contact time. Intracellular protein and potassium ion leaked out of the test bacterial cells when exposed to certain concentrations of the fraction; this is an indication of bacterial cell wall disruptions by the extract's butanolic fraction and, thus, caused a biocidal effect on the cells, as evident in the killing rate test results. PMID:25558854

  11. Electrical, optical, photocatalytic, and bactericidal properties of polyethylene glycol-assisted sol–gel synthesized ZnTiO3-implanted ZnO nanoparticles

    International Nuclear Information System (INIS)

    ZnTiO3-implanted ZnO nanoparticles were prepared by sol–gel method employing polyethylene glycol (PEG) 4000 and 20 000. The high resolution transmission electron micrographs, selected area electron diffraction pattern, energy dispersive x-ray spectra and powder x-ray diffractograms show the prepared materials as core/shell nanoparticles. Increase of the molecular mass of PEG decreases the d-spacing in ZnO of ZnTiO3-implanted ZnO and pristine ZnO nanoparticles. The charge transfer resistances of ZnTiO3-implanted ZnO nanoparticles are larger than those of pristine ZnO and precursor ZnTiO3 nanoparticles. The optical properties of ZnTiO3/ZnO nanoparticles are similar to those of pristine ZnO nanoparticles. The photocatalytic activity of ZnO is enhanced by the presence of ZnTiO3 core in the ZnO lattice. The bactericidal activity of core/shell ZnTiO3/ZnO nanoparticles is not less than that of ZnO nanoparticles. (paper)

  12. Phytic Acid and Sodium Chloride Show Marked Synergistic Bactericidal Effects against Nonadapted and Acid-Adapted Escherichia coli O157:H7 Strains.

    Science.gov (United States)

    Kim, Nam Hee; Rhee, Min Suk

    2016-02-01

    The synergistic antimicrobial effects of phytic acid (PA), a natural extract from rice bran, plus sodium chloride against Escherichia coli O157:H7 were examined. Exposure to NaCl alone at concentrations up to 36% (wt/wt) for 5 min did not reduce bacterial populations. The bactericidal effects of PA alone were much greater than those of other organic acids (acetic, citric, lactic, and malic acids) under the same experimental conditions (P 7-log CFU/ml reduction). Flow cytometry confirmed that PA disrupted the cell membrane to a greater extent than did other organic acids, although the cells remained viable. The combination of PA and NaCl induced complete disintegration of the cell membrane. By comparison, none of the other organic acids acted synergistically with NaCl, and neither did NaCl-HCl solutions at the same pH values as the test solutions of PA plus NaCl. These results suggest that PA has great potential as an effective bacterial membrane-permeabilizing agent, and we show that the combination is a promising alternative to conventional chemical disinfectants. These findings provide new insight into the utility of natural compounds as novel antimicrobial agents and increase our understanding of the mechanisms underlying the antibacterial activity of PA. PMID:26637600

  13. Preparation of bio-deep eutectic solvent triggered cephalopod shaped silver chloride-DNA hybrid material having antibacterial and bactericidal activity.

    Science.gov (United States)

    Bhatt, Jitkumar; Mondal, Dibyendu; Bhojani, Gopal; Chatterjee, Shruti; Prasad, Kamalesh

    2015-11-01

    2.5% w/w DNA (Salmon testes) was solubilized in a bio-deep eutectic solvent [(bio-DES), obtained by the complexation of choline chloride and ethylene glycol at 1:2 molar ratio] containing 1% w/w of silver chloride (AgCl) to yield a AgCl decorated DNA based hybrid material. Concentration dependent formation of AgCl crystals in the DES was observed and upon interaction with DNA it gave formation of a cephalopod shaped hybrid material. DNA was found to maintain its chemical and structural stability in the material. Further, AgCl microstructures were found to have orderly self assembled on the DNA helices indicating the electrostatic interaction between Ag(+) and phosphate side chain of DNA as a driving force for the formation of the material with ordered microstructural distribution of AgCl. Furthermore, the functionalized material exhibited excellent antibacterial and bactericidal activity against both Gram negative and Gram positive pathogenic bacteria. PMID:26249573

  14. A Teleost Bactericidal Permeability-Increasing Protein Kills Gram-Negative Bacteria, Modulates Innate Immune Response, and Enhances Resistance against Bacterial and Viral Infection.

    Science.gov (United States)

    Sun, Yuan-Yuan; Sun, Li

    2016-01-01

    Bactericidal/permeability-increasing protein (BPI) is an important factor of innate immunity that in mammals is known to take part in the clearance of invading Gram-negative bacteria. In teleost, the function of BPI is unknown. In the present work, we studied the function of tongue sole (Cynoglossus semilaevis) BPI, CsBPI. We found that CsBPI was produced extracellularly by peripheral blood leukocytes (PBL). Recombinant CsBPI (rCsBPI) was able to bind to a number of Gram-negative bacteria but not Gram-positive bacteria. Binding to bacteria led to bacterial death through membrane permeabilization and structural destruction, and the bound bacteria were more readily taken up by PBL. In vivo, rCsBPI augmented the expression of a wide arrange of genes involved in antibacterial and antiviral immunity. Furthermore, rCsBPI enhanced the resistance of tongue sole against bacterial as well as viral infection. These results indicate for the first time that a teleost BPI possesses immunoregulatory effect and plays a significant role in antibacterial and antiviral defense. PMID:27105425

  15. Relationship between complex compositions and their bactericidal activity in binary mixture of sodium 1-octanesulfonate and lanthanum (III) chloride; Okutansuruhon san natoriumu-enka rantan (III) kongo suiyoekichu ni keiseisareru fukugotai no sosei to sono sakkin sayo tono kanrensei

    Energy Technology Data Exchange (ETDEWEB)

    Kihara, K.; Furuta, T. [Saraya Co. Ltd., Osaka (Japan)

    1997-05-10

    The composition of complexes formed in aqueous solution consisting of a binary mixture of sodium 1-octanesulfonate (NaOS) and lanthanum (III) chloride (LaCl3) was studied by measuring surface tension, electric conductivity and proton spin-lattice relaxation time. In the molar ratio of octanesulfonic anion and lanthanum (III) cation below 0.1, a 3:1-complex was formed. The area per the 3:1-complex absorbed at air-water interface was 208 angstrom{sup 2} on the assumption of monomolecular layer. The formations of 2:1- and 1:1-complex were found in the vicinity of 0.5 and above 1.2 of LaCl3/NaOS, respectively. Whereas, when LaCl3 was added to 15 mol m{sup -3} NaOS, the bactericidal activity of the mixed solution against Escherichia coli ATCC 25922 markedly increased with increasing the molar ratio (LaCl3/NaOS) up to 1.0 and finally remained constant. The contribution of complexes on the bactericidal activity was estimated at 1.5:1:1 from the combination of data of complex distributions and bactericidal activity. 13 refs., 8 figs., 1 tab.

  16. Mechanisms of action of escapin, a bactericidal agent in the ink secretion of the sea hare Aplysia californica: rapid and long-lasting DNA condensation and involvement of the OxyR-regulated oxidative stress pathway.

    Science.gov (United States)

    Ko, Ko-Chun; Tai, Phang C; Derby, Charles D

    2012-04-01

    The marine snail Aplysia californica produces escapin, an L-amino acid oxidase, in its defensive ink. Escapin uses L-lysine to produce diverse products called escapin intermediate products of L-lysine (EIP-K), including α-amino-ε-caproic acid, Δ¹-piperidine-2-carboxylic acid, and Δ²-piperidine-2-carboxylic acid. EIP-K and H₂O₂ together, but neither alone, is a powerful bactericide. Here, we report bactericidal mechanisms of escapin products on Escherichia coli. We show that EIP-K and H₂O₂ together cause rapid and long-lasting DNA condensation: 2-min treatment causes significant DNA condensation and killing, and 10-min treatment causes maximal effect, lasting at least 70 h. We isolated two mutants resistant to EIP-K plus H₂O₂, both having a single missense mutation in the oxidation regulatory gene, oxyR. A complementation assay showed that the mutated gene, oxyR(A233V), renders resistance to EIP-K plus H₂O₂, and a gene dosage effect leads to reduction of resistance for strains carrying wild-type oxyR. Temperature stress with EIP-K does not produce the bactericidal effect, suggesting the effect is due to a specific response to oxidative stress. The null mutant for any single DNA-binding protein--Dps, H-NS, Hup, Him, or MukB--was not resistant to EIP-K plus H₂O₂, suggesting that no single DNA-binding protein is necessary to mediate this bactericidal effect, but allowing for the possibility that EIP-K plus H₂O₂ could function through a combination of DNA-binding proteins. The bactericidal effect of EIP-K plus H₂O₂ was eliminated by the ferrous ion chelator 1,10-phenanthroline, and it was reduced by the hydroxyl radical scavenger thiourea, suggesting hydroxyl radicals mediate the effects of EIP-K plus H₂O₂. PMID:22232273

  17. In vitro bactericidal and bacteriostatic potential of ingredients of traditional medicine obtained from Kacha area (river indus) district D.I. Khan, KPK, against human bacterial pathogens

    International Nuclear Information System (INIS)

    The aim of this study was to analyze and evaluate antimicrobial potential of medicinal plants obtained from kacha area of river indus, that are used as ingredients of traditional medicine for treatment of multiple infectious diseases. The antimicrobial activities of methanol and aqueous extracts of 5 medicinal plants of a traditional medicine were evaluated against 6 human gram positive (Staphylococcus aureus, Micrococcos luteus) and gram negative (Escherichia coli, Pseudomonas aeruginosa, Enterobacter, Klebsiella pneumoniae) pathogens. The disc diffusion and broth macro dilution assay was used to determine the zone of inhibitions and the minimum inhibitory concentration respectively. The ciprofloxacin and streptomycin were used as standard agents. Both aqueous and methanol fractions of all 5 tested plants exhibited antimicrobial activity against one or more species of microorganisms. The most active extract found wasAzadirachta indica leaves which represented widest zone of inhibition of 16(+- 0.05) mm and minimum inhibitory concentration 0.19mg/ml against Klebsie-lla pneumoniae. Calotropis procera leaves was found least active representing lowest Zones of inhibition 3.13(+- 0.05) mm and highest minimum inhibitory concentration value (20mg/ml) against test microorganisms. Over all methanol fractions of medicinal plants represented stronger biological activity against test microorganisms than aqueous extracts. A good majority of extracts were bactericidal. These results afford the ground information for potential use of crude extracts with high MIC and MBC values. Moreover a synergistic effect is expected when used in combination. For this further attempt are in progress to investigate antimicrobial potential of combination medicine. (author)

  18. Correlation between serum bactericidal activity against Neisseria meningitidis serogroups A, C, W-135 and Y measured using human versus rabbit serum as the complement source.

    Science.gov (United States)

    Gill, C J; Ram, S; Welsch, J A; Detora, L; Anemona, A

    2011-12-01

    The surrogate of protection against invasive meningococcal disease is the presence of serum bactericidal activity (SBA) at a titer ≥4 in an assay using human serum as the complement source (hSBA). However, for various practical and logistical reasons, many meningococcal vaccines in use today were licensed based on a modified SBA assay that used baby rabbit serum as the complement source (rSBA). To assess the strength of correlation between the two assay systems for serogroups A, C, W-135 and Y, we analyzed a subset of samples from adolescent subjects enrolled in a Phase II study of Novartis' MenACWY-CRM conjugate vaccine vs. an ACWY polysaccharide vaccine; samples were analyzed in parallel using hSBA and rSBA. We compared geometric mean titers (GMTs), calculated Pearson correlation coefficients between paired hSBA and rSBA results, and calculated sensitivity/specificity and likelihood ratios for an rSBA ≥8 or ≥128 for classifying hSBA ≥4, taking hSBA as the 'gold standard'. Correlations between hSBA and rSBA ranged from 0.46 to 0.78 for serogroup C, but were weaker for serogroups A, W-135 and Y (range -0.15 to 0.57). In post vaccination samples, nearly all subjects had rSBA titers ≥8, though up to 15% remained seronegative by hSBA. In post vaccination settings, rSBA titers at ≥8 or ≥128 was highly sensitive for an hSBA titer ≥4, but non-specific. In conclusion, results generated by rSBA did not accurately classify serostatus according to hSBA for serogroups A, W-135 and Y. PMID:22075087

  19. In vitro analysis on bactericidal screening and antioxidant potentiality of leaf and root extracts of Thottea siliquosa (Lam.) Ding Hou. An ethnobotanical plant

    Institute of Scientific and Technical Information of China (English)

    Saiba Abdul Wahab Nusaiba; Kumaraswamy Murugan

    2013-01-01

    Objective: Natural products of plant origin are potential source of novel antimicrobial and antioxidative agents. Thottea siliquosa (Lam.) Ding Hou. (T. siliquosa). A medicinal herb used by local tribals for treating various ailments. The present study aims at the phytochemical screening, GC-MS analysis, in vitro antibacterial activity and antioxidant potentiality of root and leaf extracts of T. siliquosa.Methods:Hot continuous Soxhlet extraction, GC-MS analysis, antibacterial analysis by disc diffusion, microdilution assay and antioxidant potentialities by hydroxyl radical and nitric oxide radical scavenging. The data was statistically analyzed. Results: Phytochemical screening of the ethyl acetate and methanolic extract of leaf and root revealed the presence of phenols, alkaloids, tannins and saponin. The extract revealed a pool of phytochemicals by comparison with authentic standards from spectral library. Both the extracts has shown their broad spectrum of inhibition against the selected bacteria Staphylococcus aureus,Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia compared with standard antibiotic drug streptomycin. The extracts showed antioxidant activity by scavenging of free radicals such as hydroxyl and nitric oxide. The IC50 values of the ethyl acetate extracts leaf and root and standard in this assay were 167.5±0.67, 99.4±1.2, 192±2.5 µg/mL respectively. Similarly those methanolic extracts of leaf and root were 269.5±0.89 and 289.1±2.66 µg/mL respectively. Similarly, ethyl acetate and methanolic extracts also caused a moderate dose-dependent inhibition of nitric oxide with an IC50 range 65.5±1.55 to 148 ±3.09 µg/mL. The inhibitory activities were found to be dose dependent.Conclusion:The present study provides evidence that ethyl acetate and methanol extract of leaf and root of T. siliquosa are potential source of natural antioxidants and bactericidal nature. It is essential that research should continue to isolate and purify

  20. 天然高分子改性异喹啉季铵盐对SRB杀菌性能及机理的研究%A Study of Bactericidal Effect of Natural Polymeric Modified Isoquinoline Quaternary Ammonium Salt on Sulfate Reducing Bacteria(SRB) and Mechanism

    Institute of Scientific and Technical Information of China (English)

    潘碌亭; 肖锦

    2001-01-01

    The bactericidal effect of natural polymeric modified isoquinoline quaternary ammonium salt(FIQ-C)on sulfate reducing bacteria (SRB) was studied using the vanishing- dilution method. Factors affecting the bactericidal ef- ficiency were investigated, the bectericidal ability of FIQ-C was compared with that of 1227, and the bactericidal mechanism of FIQ-C was approached. The result shows that FIQ - C has a good bactericidal effect on the SRB in sim- ulated oil field waste water and that when the addition of FIQ - C is 5 mg/L, the bactericidal rate may be 99.9% or higher.%采用绝迹稀释法研究了天然高分子改性异喹啉季铵盐(FIQ-C)对硫酸盐还原菌(SRB)的杀灭性能。考察了各种因素对杀菌性能的影响,比较了药剂FIQ-C与1227的杀菌能力,探讨了FIQ-C的杀菌机理。结果表明,药FIQ-C对模拟油田废水中SRB有良好的杀灭性能,当FIQ-C投加量为5 mg/L时,杀菌率可达99.9%以上。

  1. Bactericidal Effect Test on Disinfectant Compound of benzalkonium Bromide-Allicin%苯扎溴铵—大蒜素复方消毒剂的杀菌效果试验

    Institute of Scientific and Technical Information of China (English)

    李孝文; 陈峰; 董伟; 王晶; 殷铭阳; 田世杰; 孙志良

    2011-01-01

    为了探明苯扎溴铵—大蒜素复方消毒剂的杀菌效果,根据兽用消毒剂鉴定技术规范的相关规定,用不同稀释倍数(500、1000、2000、4000倍)的该消毒剂在不同时间段(1、5、10、20 min)对5种细菌(金黄色葡萄球菌、大肠杆菌、多杀性巴氏杆菌、溶血性链球菌C型及蜡样芽孢杆菌)进行杀菌效果试验,同时以苯扎溴铵和大蒜油为对照试验组,观察和评价苯扎溴铵—大蒜素复方消毒剂的杀菌效果.结果表明在2000倍稀释的状态下该复方消毒剂对以上5种细菌表现出了完全的杀菌效果.因此,苯扎溴铵—大蒜素复方消毒剂在2000倍的稀释状态下能达到良好的杀菌效果,便于临床应用.%In order to proven the bactericidal effect of disinfectant compound of Benzalkonium bromide-Allicin,regulations of identification of technical specifications veterinary disinfectant were to be used. Five kinds of bacteria (Staphylococcus aureus, Escherichia coli ,Pasteurella multocida ,Streptococcus-C and Bacilluscereus) at different time periods (1.5,10,20 min)are test by the sterilization way in different dilutions (500,1000,2000,4000 times) of the disinfectant. At the same time benzalkonium bromide and garlic oil were used as the control test group. The bactericidal effect test of disinfectant compound of Benzalkonium bromide-Allicin was observed and evaluated. The results show that the disinfectant compound in 2000 dilution of the bactericidal effect achieved the standard. Therefore, the disinfectant compound in 2000 dilution can be up to good results,and can be used in clinical.

  2. Characterization of diverse subvariants of the meningococcal factor H (fH) binding protein for their ability to bind fH, to mediate serum resistance, and to induce bactericidal antibodies.

    Science.gov (United States)

    Seib, Kate L; Brunelli, Brunella; Brogioni, Barbara; Palumbo, Emmanuelle; Bambini, Stefania; Muzzi, Alessandro; DiMarcello, Federica; Marchi, Sara; van der Ende, Arie; Aricó, Beatrice; Savino, Silvana; Scarselli, Maria; Comanducci, Maurizio; Rappuoli, Rino; Giuliani, Marzia M; Pizza, Mariagrazia

    2011-02-01

    Neisseria meningitidis is a commensal of the human nasopharynx but is also a major cause of septicemia and meningitis. The meningococcal factor H binding protein (fHbp) binds human factor H (fH), enabling downregulation of complement activation on the bacterial surface. fHbp is a component of two serogroup B meningococcal vaccines currently in clinical development. Here we characterize 12 fHbp subvariants for their level of surface exposure and ability to bind fH, to mediate serum resistance, and to induce bactericidal antibodies. Flow cytometry and Western analysis revealed that all strains examined expressed fHbp on their surface to different extents and bound fH in an fHbp-dependent manner. However, differences in fH binding did not always correlate with the level of fHbp expression, indicating that this is not the only factor affecting the amount of fH bound. To overcome the issue of strain variability in fHbp expression, the MC58ΔfHbp strain was genetically engineered to express different subvariants from a constitutive heterologous promoter. These recombinant strains were characterized for fH binding, and the data confirmed that each subvariant binds different levels of fH. Surface plasmon resonance revealed differences in the stability of the fHbp-fH complexes that ranged over 2 orders of magnitude, indicating that differences in residues between and within variant groups can influence fH binding. Interestingly, the level of survival in human sera of recombinant MC58 strains expressing diverse subvariants did not correlate with the level of fH binding, suggesting that the interaction of fHbp with fH is not the only function of fHbp that influences serum resistance. Furthermore, cross-reactive bactericidal activity was seen within each variant group, although the degree of activity varied, suggesting that amino acid differences within each variant group influence the bactericidal antibody response. PMID:21149595

  3. EVALUACIÓN in vitro DEL EFECTO BACTERICIDA DE CEPAS NATIVAS DE Lactobacillus sp. CONTRA Salmonella sp. y Escherichia coli In vitro EVALUATION OF THE BACTERICIDAL EFFECT OF NATIVE STOCKS OF Lactobacillus sp. AGAINST Salmonela sp. AND Echerichia coli

    Directory of Open Access Journals (Sweden)

    Ana Cristina Estrada Maldonado

    2005-06-01

    Full Text Available En esta investigación se trabajó con dos cepas nativas de Lactobacillus plantarum y Lactobacillus brevis, aisladas de productos fermentados; estas crecen en medios de cultivo y producen un extracto complejo de ácidos orgánicos y péptidos con actividad bactericida. Los extractos de estas cepas mostraron capacidad bactericida frente a Salmonella sp. y Escherichia coli. Los ensayos para determinar su acción se realizaron con el extracto crudo y centrifugado provenientes de cada una de las cepas, a diferentes tiempos de almacenamiento, temperatura y pH. Se observó una mejor actividad antibacteriana y estabilidad de la actividad, en el extracto crudo almacenado a temperatura de 0ºC y 4ºC. A pH 5.5 se presento la mejor actividad en los dos extractos frente a las cepas de estudio. Se concluyó que los extractos sintetizados por ambas cepas tienen un alto potencial bactericida contra estas dos patógenos que son responsables de toxi-infecciones alimentarias.In this investigation, two native stocks of Lactobacillus plantarum and Lactobacillus brevis isolated from fermented products were studied; these grow in culture media and produce a complex extract of organic acids and peptides with bactericidal activity. The extracts of these stocks showed bactericidal capacity with Salmonella sp. and Escherichia coli. The tests to determine their action were made with crude and centrifuged extract originating of each one of the stocks, with different storage times, temperatures and pHs. A superior antibacterial activity and stability of the activity was observed in the crude extract stored in temperatures of 0ºC and 4ºC. With pH 5,5 the best activity of the two extracts against the study stocks was obtained. It is concluded that the extracts synthesized by both stocks have a high bactericidal potential against these two pathogens that are responsible for nutritional toxi-infections.

  4. Bioactivity of Several Bactericides against Xanthomonas campestris pv.citri%几种杀菌剂对柑桔溃疡病的生物活性

    Institute of Scientific and Technical Information of China (English)

    孙惠敏; 李保同; 郭明程; 陈慈相; 谢金招; 刘德力

    2011-01-01

    为筛选防治柑桔溃疡病的有效药剂,按大田推荐使用浓度,用抑菌圈法测定17种非铜药剂和5种含铜药剂对柑桔溃疡病的毒力,并研究7种非铜药剂田间防治效果.结果表明,代森锰锌、福美双、福美双·溴菌腈、农用链霉素、金核霉素和琥胶肥酸铜·乙磷铝·硫酸锌抑菌作用最强,其次为福美双·福美锌、大蒜素、络氨铜·络氨锌和盐酸吗啉胍·乙酸铜,过氧乙酸、噻唑锌、春雷菌素、中生菌素、琥珀酸铜和噻菌铜有微弱的抑菌作用,百菌清、多菌灵、苯醚甲环唑、叶青双、复硝酚钠和井冈霉素无抑菌作用.大田试验结果表明,30%金核霉素WP 500 mg/L和72%农用链霉素WP 200 mg/L处理对柑桔溃病的防效分别为76.34%和74.94%,显著优于其它药剂处理;80%代森锰锌WP 2000 mg/L、50%福美双WP 400 mg/L和50%福美双·溴菌腈WP 500 mg/L处理对柑桔溃病的防效分别为70.36%、66.55%和69.37%,与对照含铜药剂20%噻菌铜SC 67 mg/L处理无显著差异;大蒜素和叶青双对柑桔溃病防效较差,6%大蒜素EC 120 mg/L和20%叶青双WP 400 mg/L处理对柑桔溃病的防效分别为41.84%和21.82%,显著低于对照含铜药剂20%噻菌铜SC 67 mg/L处理.%In order to screen effective bactericides against Xanthomonas camprestris pv. citri, the toxicity of 17 non - copper fungicides and 5 copper fungicides against the strain of X. campestris pv. citri in the greenhouse were determined by the method of inhibition zone, and the efficacy of 7 non - copper fungicides in the field was tested. The results showed that manzoceb, thiram, thiram -bromothalonil, agricultural streptomycin, aureonucleomycin and DT -fosetyl -aluminium -zinc suffate had the strongest inhibitory effect on the pathogen, thiram- ziram, allicin, cupric tetramminosuffate- zinc tetramminosuffate and moroxydine hydrochloride- cupric acetate had relatively strong inhibitory effect, peracetic acid, Zn thiazole, Kasugamycin, Zhong

  5. The HICN liquid bactericidal effect observed against Mycobacterium tuberculosis%HICN液对结核分枝杆菌杀菌效果观察

    Institute of Scientific and Technical Information of China (English)

    胡永林; 韦永慧

    2012-01-01

      目的:探究用HICN液对结核分枝杆菌的杀菌效果。方法:将罗氏培根基上生长的典型结核分枝杆菌菌落,制成约1个麦氏浊度浓度菌悬液,试验组用两倍菌悬液体积的HICN液分别处理结核分枝杆菌菌液5min、10min、15min、20min、25min、30min、35min、40min、45min、50min、55min、60min后,接种于罗氏(L-J)培养基斜面,对照组用生理盐水代替HICN液。一并放到37℃培养箱培养42d后观察生长情况,并取培养后的菌落涂片染色镜检。结果:对照组各培养管结核分枝杆菌生长良好,菜花状菌落典型,布满整个培养基,涂片抗酸染色镜检可见典型结核分枝杆菌形态;经HICN液分别处理5min、10min、15min、20min后观察组各管结核分枝杆菌均有不同程度生长,但生长情况依次呈递减趋势,涂片镜检可见结核分枝杆菌形态;经HICN液分别处理25min、30min、35min、40min、45min、50min、55min、60min后观察组各管无菌落生长。结论:两倍于菌悬液浓度的HICN液对结核分枝杆菌有杀菌作用,杀菌时间≥25分钟,因HICN液是较好的溶血剂,实验室可采用HICN液处理带血标本进行结核分枝杆菌的涂片检查。%  Objective To explore the use the HICN liquid bactericidal effect against Mycobacterium tuberculosis. Method The typical M. tuberculosis colonies grown on the foundation of Roche training, made about a Maxwel turbidity concentration of bacterial suspension, the test group with the the HICN solution twice the volume of bacterial suspension, respectively, deal with Mycobacterium tuberculosis bacteria 5min, 10min, 15min, 20min, 25min, 30min, 35min, 40min, 45min, 50min, 55min, 60min after inoculation Roche (L-J) medium slant in the control group with saline instead of HICN liquid. Together into the 37℃incubator 42d observe the growth of smear staining and cultured colonies. Results In the control group, each culture tube of

  6. PILOT SCALE PRODUCTION OF DISSYMMETRIC GEMINI QUATERNARY AMMONIUM SALT AND ITS BACTERICIDAL PERFORMANCE%非对称双子季铵盐杀菌剂的中试合成及杀菌效果

    Institute of Scientific and Technical Information of China (English)

    刘晓峰; 李友明; 万小芳

    2012-01-01

    为了解决长期使用1227季铵盐杀菌剂带来的微生物抗药性问题,以十二/十四烷基叔胺为原料,和环氧氯丙烷通过一步法工艺合成了一种非对称双子季铵盐,并成功进行了100 kg的中试生产,目的产品转化率高达95%.此外,通过异养菌和铁细菌静态杀菌实验研究该非对称双子季铵盐的杀菌性能.实验结果表明:在40 mg/L剂量,对异养菌的杀菌率在8h和16h分别为90.43%和80%以上;4h时对铁细菌的杀菌率高达96.79%,杀菌率在44 h内能维持在95%~100%之间,优于常用杀菌剂1227的杀菌效果.最后,在“三泥”回收装置的循环水系统中投加该杀菌剂的应用试验表明:虽然夏季循环水的高温使细菌更易繁殖,但非对称双子季铵盐依然能将异养菌控制在1 000个/mL以下,有效抑制细菌的生长,杀菌率达到95%.%The dissymmetric Gemini quaternary ammonium salt was synthesized by one-step process from 12/14 alkyl tertiary amine and epichlorohydrin. A pilot scale production of 100 kilogram was also succeeded with the product conversion of 95%. Besides, its bactericidal capability was studied according to the static sterilization experiment of heterotrophic bacteria and iron bacteria. The results showed that the sterilization rate of heterotrophic bacteria was 90. 43% in 8 hours and over 80% in 16 hours, respectively. To the iron bacteria, the sterilization rate was easily up to 96. 79% in 4 hours and was maintained between 95%- 100% within 44 hours. The bactericidal capability is superior to the conventional bactericide 1227. Finally, during the bactericide was added into the "three sludge" recycling water, the experimental results showed that this product could keep the quantities of heterotroph below 1 000 per mL although the higher temperature in summer is beneficial to reproduction of all kinds of bacterias, which could restrain the growth of bacteria effectively with the sterilizing rate up to 95%.

  7. Bactericidal Activities of Spicy Essential Oils on Microorganisms in Crude Food%香辛料精油成分对生鲜食品中有害菌杀灭活性研究

    Institute of Scientific and Technical Information of China (English)

    段雪娟; 吴克刚; 柴向华

    2012-01-01

    Bactericidal activities of seven spicy essential oil components on five microorganisms (Escherichia Coli, Staphylococcus Awrous, Saimonella, Listcria monocytogenes, Vibrio Parahemolyticus) were studied by plate dilution method and transferring substrate cob method. Results showed that salicylaldehyde had the best bactericidal activity,followed successively by thymol, cin-namic aldehyde, anethole, eugenol, citral, vanillin. The optimal composite essential oil ( salicylaldehyde: cinnamic aldehyde: thymol: anethole 2:5: 20: 5. ) was obtained through orthogonal test. The minimum bactericidal mass concentration of the composite essential oil for killing five pathogens was 0.25 mg/L, only 1/2 of that of salicylaldehyde. Synergistic sterilization effects of composite essential oil was analyzed. The composite essential oil showed a strong synergistic effect on Listeria monocytogenes, an additive effect on Staphylococcus Aurous , Escherichia Coli and Vibrio Parahemolyticus, and unrelated effect on Salmonella.%采用平板稀释法和菌块转移法研究了百里香酚、丁香酚、肉桂醛、茴香脑、水杨醛、柠檬醛、香兰素7种食用植物精油组分对大肠杆菌、金黄色葡萄球菌、沙门氏菌、单增李斯特菌、副溶血性弧菌等生鲜食品常见5种有害菌的杀灭活性.实验结果表明,水杨醛对5种有害菌的综合杀灭能力最强,然后依次是百里香酚、肉桂醛、茴香脑、丁香酚、柠檬醛、香兰素.通过正交试验将水杨醛、肉桂醛、百里香酚、茴香脑复配,得到最佳组合是为:水杨醛、肉桂醛、百里香酚、茴香脑的质量比为2:5:20:5,其杀灭所有供试菌的最低质量浓度为0.25 mg/L,仅为杀菌效果最好的单一水杨醛浓度的1/2.通过对香辛料精油成分杀菌作用协同效应分析得出,复配的香辛精油对单增李斯特菌的杀灭表现出很强的协同增效作用效果,对金黄色葡萄球菌、大肠杆菌和副溶血性弧菌的杀灭

  8. Study on the effects of S2- ions on the capacities of corrosion inhibitor,scale inhibitor and bactericide commonly used in circulating water%S2-对循环水常用缓蚀、阻垢及杀菌剂相关性能的影响研究

    Institute of Scientific and Technical Information of China (English)

    王亭; 郦和生

    2012-01-01

    通过静态实验研究了S2-对循环水常用缓蚀、阻垢和杀菌剂性能的影响.结果表明:S2-可使常见缓蚀单剂的缓蚀性能明显降低,在S2-质量浓度低于1 mg/L时,投加100 mg/L复合缓蚀阻垢剂YSW105可使水体的腐蚀速度低于0.1 mm/a;S2-对水稳剂的阻碳酸钙垢和阻磷酸钙垢性能影响不大,常用共聚物难以在含S2-水体中稳定锌盐;S2-对常用杀菌剂的杀菌性能影响均较大,质量浓度为3 mg/L时即可使其基本丧失杀菌性能.%The effects of S2- on the corrosion inhibitor,scale inhibitor and bactericide commonly used in circulating water have been studied by static tests. The results show that S2- can obviously reduce the corrosion inhibiting capacity of common single-dosed corrosion inhibitor. Adding 100 mg/L of complex scale and corrosion inhibitor YSW105 could make the corrosion rate less than 0.1 mm/a,when S2- concentration is less than 1 mg/L. S2-has little influence on the capacities for CaCO3 scale inhibiting & Ca3 (PO4)2 scale inhibiting of water stablizers, but using copolymers frequently is difficult to stabilize zinc salts in water body that contains S2-. S2- has great effects on the bactericidal capacity for the commonly used bactericides. When S2- concentration comes to 3 mg/L,it can basically make the bactericides lose their bactericidal capacity.

  9. 17%EDTA与1%NaOCl组合用于根管超声冲洗抗菌效果的临床研究%Bactericidal effect of 17% EDTA combined with 1% NaOCl as irrigant of root canals

    Institute of Scientific and Technical Information of China (English)

    黄辉; 李慧; 张行炜; 刘漪; 张晓希; 范华南

    2009-01-01

    Objective To evaluate the bactericidal effect of 17% EDTA combined with 1% NaOCl in ultrasonic irrigation of root canal.Methods Totally 100 single-rooted teeth in 100 patients with chronic periapical periodontitis were divided into five groups randomly of 20 teeth each. All root canals were instrumented by hand with stainless steel endodontic instruments and irrigated by ultrasound with 2.5% NaOCl (group A),1% NaOCl (group B), 17% EDTA+1% NaOCl (group C), 17% EDTA (group D), and saline(group E). Totally 30 μl of liquid sample was obtained from each root canal and examined for anaerobic bacteria colony counting before and after root canal instrumentation.Results After root canal instrumentation, the number of anaerobic bacteria colony was significantly reduced in all 5 groups (P<0.01) . The colony number in group C was less than that in group B (P<0.05), and than that in group D and E (P<0.01), there was no difference between group A and group C (P>0.05).Conclusion Ultrasonic combined with 17% EDTA+1% NaOCl irrigation has better bactericidal effects of root canal irrigation.%目的 研究17%EDTA+1%NaOCl与超声波联合应用杀灭感染根管内厌氧菌的效果.方法 将100例慢性根尖周炎患者共100颗患牙随机分为A组(2.5%NaOCl)、B组(1%NaOCl)、C组(17%EDTA+1%NaOCl)、D组(17%EDTA)、E组(生理盐水)5组,每组各20颗患牙,采用手持器械预备根管后,分别采用2.5%NaOCl、1%NaOCl、17%EDTA+1%NaOCl、17%EDTA、生理盐水超声法冲洗根管,根管预备前后分别取样进行厌氧培养.结果 根管预备前后,五组根管内厌氧菌减少程度之间有显著性差异(P<0.01),其中C组(17%EDTA+1%NaOCl组)厌氧菌的减少程度明显大于B组(1%NaOCl组)(P<0.05),显著大于D组(17%EDTA组)和E组(生理盐水组)(P<0.01),与A组(2.5%NaOCl组)之间无显著性差异(P>0.05).结论 17%EDTA+1%NaOCl与超声波联合应用可有效杀灭根管内的厌氧菌,其抗

  10. Evaluación de la Actividad Bactericida de Bacterias Ácido Lácticas Aisladas en Calostro de Cerdas Frente a Salmonella typhimurium / Bactericidal Evaluation of Lactic Acid Bacteria Isolated in Sow Colostrum Against Salmonella tiphymurium

    Directory of Open Access Journals (Sweden)

    Juliana María Vélez Zea

    2014-12-01

    Full Text Available Resumen. En los sistemas de crianza intensiva especialmenteen cerdos, la resistencia antimicrobiana de algunas bacteriaspatógenas, se ha convertido en un problema mundial, tantopara los productores como para los consumidores. El uso demicroorganismos probióticos aislados de calostro de cerda criadasen sistemas intensivos han demostrado eficacia en la inhibicióndel crecimiento de algunos patógenos entéricos. Se eligierondos cepas denominadas como BAL1 y BAL3, a las cuales se lesevaluó el potencial bactericida de los extractos bacterianos sobreel patógeno Salmonella thipymurium, por el método de difusiónen pozos en agar Mueller Hinton. Los extractos se obtuvieronajustando el inóculo a 0,5 McF en caldo MRS, centrifugados a6.000 rpm por 5 minutos y filtrados con membrana de 0,2 μm.Ambos extractos mostraron tener un alto potencial bactericidafrente a esta bacteria, con promedios de halo de inhibición de 11mm in vitro.  / Abstract. In intensive farming systems especially in pigs, theantimicrobial resistance of some pathogenic bacteria has becomea global problem, both for producers and consumers. The use ofprobiotic microorganisms isolated of sow colostrum in intensivefarms have demonstrated the ability to inhibit the growth of someenteric pathogens. Two of these strains named as BAL1 and BAL3were chosen for evaluate the bactericidal potential of their extractsagainst the pathogen Salmonella typhimurium. The well diffusionmethod, in Mueller Hinton agar was used. The BAL extractswere obtained, adjusted the BAL inoculum in MRS broth at 0.5MacFarland, centrifuged at 6,000 rpm for 5 minutes and filteredwith a 0.2 um membrane. Both extracts demonstrated to havebactericidal activity against this bacterium with mean inhibitionhalos of 11 mm in vitro.

  11. Deactivation efficiency of stabilized bactericidal emulsions.

    Science.gov (United States)

    Vyhnalkova, Renata; Eisenberg, Adi; van de Ven, Theo G M

    2011-09-20

    Biocide emulsions stabilized with various stabilizing agents were prepared and characterized, and their efficiency in bacteria deactivation was evaluated. A number of stabilizing agents were tested for their stabilizing effect on emulsions of thiocyanomethylthiobenzothiazole (TCMTB) biocide. Two agents, the most successful in stabilizing the biocide, were chosen for further studies: high molecular weight polyethyleneimine (PEI) and an amphiphilic block copolymer of poly(caprolactone)-b-poly(acrylic acid) (PCL(33)-b-PAA(33)). The emulsion droplet sizes varied between 325 and 500 nm. Deactivation of bacteria was studied by exposing E. coli ATCC 11229 bacteria dispersions to emulsions stabilized by positively charged PEI or negatively charged PCL-b-PAA micelles and by measuring their absorbance; E. coli do not grow with time in the presence of biocide emulsions. PEI molecules alone act as biocide and deactivate the bacteria. PCL-b-PAA micelles as stabilizing agent do not affect the growth of the E. coli ; bacteria are deactivated by TCMTB released from the emulsion droplets. The kinetics of emulsion dissolution studies revealed for both stabilizing agents a decrease in droplet size with time while the emulsions were subjected to dialysis. The biocide was released from the emulsions within ∼250 min; the droplet shells consist mostly of PEI or PCL-b-PAA insoluble complexes with the biocide, which do not dissolve during dialysis. SEM images confirm the presence of residual crumbled shells with holes after 24 h of dialysis. PMID:21823610

  12. The bactericidal effect of shock waves

    International Nuclear Information System (INIS)

    There are a variety of theories relating to the origins of life on our home planet, some of which discuss the possibility that life may have been spread via inter-planetary bodies. There have been a number of investigations into the ability of life to withstand the likely conditions generated by asteroid impact (both contained in the impactor and buried beneath the planet surface). Previously published data regarding the ability of bacteria to survive such applied shockwaves has produced conflicting conclusions. The work presented here used an established and published technique in combination with a single stage gas gun, to shock and subsequently recover Escherichia coli populations suspended in a phosphate buffered saline solution. Peak pressure across the sample region was calculated via numerical modelling. Survival data against peak sample pressure for recovered samples is presented alongside control tests. SEM micrographs of shocked samples are presented alongside control sets to highlight key differences between cells in each case

  13. Electrospun biodegradable polymers loaded with bactericide agents

    OpenAIRE

    Ramaz Katsarava; del Valle, Luís J; Lourdes Franco; Jordi Puiggalí

    2016-01-01

    Development of materials with an antimicrobial activity is fundamental for different sectors, including medicine and health care, water and air treatment, and food packaging. Electrospinning is a versatile and economic technique that allows the incorporation of different natural, industrial, and clinical agents into a wide variety of polymers and blends in the form of micro/nanofibers. Furthermore, the technique is versatile since different constructs (e.g. those derived from single electrosp...

  14. Cloning and characterization of two lipopolysaccharide-binding protein/bactericidal permeability-increasing protein (LBP/BPI) genes from the sea cucumber Apostichopus japonicus with diversified function in modulating ROS production.

    Science.gov (United States)

    Shao, Yina; Li, Chenghua; Che, Zhongjie; Zhang, Pengjuan; Zhang, Weiwei; Duan, Xuemei; Li, Ye

    2015-09-01

    Lipopolysaccharide-binding protein and bactericidal permeability-increasing protein (LBP/BPI) play crucial role in modulating cellular signals in response to Gram-negative bacteria infection. In the present study, two isoforms of LBP/BPI genes (designated as AjLBP/BPI1 and AjLBP/BPI2, respectively) were cloned from the sea cucumber Apostichopus japonicus by RACE approach. The full-length cDNAs of AjLBP/BPI1 and AjLBP/BPI2 were of 1479 and 1455 bp and encoded two secreted proteins of 492 and 484 amino acid residues, respectively. Signal peptide, two BPI/LBP/CETP and one central domain were totally conserved in the deduced amino acid of AjLBP/BPI1 and AjLBP/BPI2. Phylogentic analysis further supported that AjLBP/BPI1 and AjLBP/BPI2 belonged to new members of invertebrates LBP/BPI family. Spatial expression analysis revealed that both AjLBP/BPI1 and AjLBP/BPI2 were ubiquitously expressed in all examined tissues with the larger magnitude in AjLBP/BPI1. The Vibrio splenfidus challenge and LPS stimulation could significantly up-regulate the mRNA expression of both AjLBP/BPI1 and AjLBP/BPI2, with the increase of AjLBP/BPI2 expression occurred earlier than that of AjLBP/BPI1. More importantly, we found that LPS induced ROS production was markedly depressed after AjLBP/BPI1 knock-down, but there was no significant change by AjLBP/BPI2 silencing. Consistently, the expression level of unclassified AjToll, not AjTLR3, was tightly correlated with that of AjLBP/BPI1. Silencing the AjToll also depressed the ROS production in the cultured coelomocytes. All these results indicated that AjLBP/BPI1 and AjLBP/BPI2 probably played distinct roles in bacterial mediating immune response in sea cucumber, and AjLBP/BPI1 depressed coelomocytes ROS production via modulating AjToll cascade. PMID:25956196

  15. Sustained release of bactericidal concentrations of penicillin in the pleural space via an antibiotic-eluting pigtail catheter coated with electrospun nanofibers: results from in vivo and in vitro studies

    Directory of Open Access Journals (Sweden)

    Chao YK

    2015-05-01

    Full Text Available Yin-Kai Chao,1 Cheng-Hung Lee,2 Kuo-Sheng Liu,1 Yi-Chuan Wang,3 Chih-Wei Wang,4 Shih-Jung Liu3 1Department of Thoracic and Cardiovascular Surgery, Chang Gung Memorial Hospital-Linkou, College of Medicine, Chang Gung University, Taoyuan, Taiwan; 2Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital-Linkou, College of Medicine, Chang Gung University, Taoyuan, Taiwan; 3Department of Mechanical Engineering, Chang Gung University, Taoyuan, Taiwan; 4Department of Pathology, Chang Gung Memorial Hospital-Linkou, College of Medicine, Chang Gung University, Taoyuan, Taiwan Background: Inadequate intrapleural drug concentrations caused by poor penetration of systemic antibiotics into the pleural cavity is a major cause of treatment failure in empyema. Herein, we describe a novel antibiotic-eluting pigtail catheter coated with electrospun nanofibers used for the sustained release of bactericidal concentrations of penicillin in the pleural space.Methods: Electrospun nanofibers prepared using polylactide-polyglycolide copolymer and penicillin G sodium dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol were used to coat the surface of an Fr6 pigtail catheter. The in vitro patterns of drug release were tested by placing the catheter in phosphate-buffered saline. In vivo studies were performed using rabbits treated with penicillin either intrapleurally (Group 1, 20 mg delivered through the catheter or systemically (Group 2, intramuscular injection, 10 mg/kg. Penicillin concentrations in the serum and pleural fluid were then measured and compared.Results: In vitro studies revealed a burst release of penicillin (10% of the total dose occurring in the first 24 hours, followed by a sustained release in the subsequent 30 days. Intrapleural drug levels were significantly higher in Group 1 than in Group 2 (P<0.001. In the former, penicillin concentrations remained above the minimum inhibitory concentration breakpoint throughout the entire

  16. The Evaluation of Teat Dipping Coating Agent for Cow Mastitis Pathogens Bactericidal and Bacteriostatic Test in Vitro%聚维酮碘乳头药浴涂膜剂对奶牛乳房炎致病菌体外抑菌效果评价

    Institute of Scientific and Technical Information of China (English)

    周庆民; 冯万宇; 徐馨; 侯美如; 黄健

    2015-01-01

    This study aims to understand in vitro bacteriostasis effectiveness(MIC and MBC)of the teat dipping coating agent on major pathogens(Escherichia coli, Staphylococcus aureus, Streptococcus agalactiaeand Streptococcus dysgalactiae)andprovideacertainofscientiifcevidence.Utilizing10timesmicrodilutionmethod, we determine in vitro effectiveness of the teat dipping coating agent on clinical isolates strain of the major cows mastitis. In order to compare bacteriostasis effectiveness of the teat dipping coating agent and antibiotics,we design the control group-ceftiofur and penicillin. The results show that in vitro the agent has signiifcant bacteriostasis effects on four major pathogens of cow mastitis, and the bactericidal and bacteriostatic concentration is lower than ceftiofur and penicillin.%本试验采用10倍稀释法进行了乳头药浴涂膜剂对奶牛乳房炎临床分离菌株(大肠杆菌、金黄色葡萄球菌、无乳链球菌及停乳链球菌)的体外抑菌效果测定。结果显示,乳头药浴涂膜剂对四种致病菌有良好的体外抑菌和杀菌作用,其抑杀菌浓度低于头孢噻呋和青霉素。

  17. 淋病奈瑟菌rmp基因缺失突变株的构建及其抗体杀菌作用研究%Construction of a recombinant Neisseria gonorrhoeae strain with rmp gene deletion and study on the bactericidal activities of its antibodies

    Institute of Scientific and Technical Information of China (English)

    李国才; 解如山; 冒艳丽; 刘双喜; 焦红梅; 陈红菊; 严华; 季明春

    2013-01-01

    Objective To study the role of the outer membrane protein Rmp of Neisseria gonor-rhoeae strain in immunosuppression and the strategy of eliminating it .Methods The rmp gene of Neisseria gonorrhoeae strain was amplified by PCR and inserted into pMD 19-T vector .The recombinant vector pMD 19△rmp∷Kan containing Kan and the 5′-and 3′-flanking regions of rmp (△rmp∷Kan) was constructed by replacing 200 nucleotide residues of pMD 19-rmp with kanamycin resistance gene Kan and transformed into Neisseria gonorrhoeae WHO-A strain.PCR and Western blot assay were used to screen and identify the re-combinant mutant strains that could not express Rmp .Mice were immunized with mutant strains and bacteri-cidal activities of the immune sera were detected by antibody-mediated complement-dependent cytotoxicity assay.Results The mutant strains that could not encode Rmp were successfully constructed .Antibodies in-duced by mutant strains showed stronger bactericidal activity against Neisseria gonorrhoeae in comparison with those induced by wild strains .Conclusion The recombinant Neisseria gonorrhoeae strain with rmp gene de-letion might eliminate the immunosuppressive effects of Rmp expressed in wild gonococcal strains , which provides a reference for further development of novel live attenuated whole-cell vaccines of Neisseria gonor-rhoeae.%  目的研究淋病奈瑟菌的外膜蛋白Rmp在免疫阻抑中的作用及其消除策略。方法PCR扩增淋病奈瑟菌rmp基因,将rmp中间200个核苷酸残基用卡那霉素抗性基因Kan取代,含rmp两侧侧翼区和Kan的DNA片段△rmp∷Kan转化淋病奈瑟菌 WHO-A菌株,PCR和Western blot 鉴定野生rmp被突变基因(△rmp∷Kan)取代并不能表达Rmp的突变株。突变株免疫小鼠,并用抗体介导的补体杀菌作用研究免疫血清的抗菌活性。结果构建了rmp基因缺失的淋病奈瑟菌突变株,突变株诱生的抗体具有更强的杀伤淋病奈瑟菌活性。结论淋

  18. Phosphorylcholine Allows for Evasion of Bactericidal Antibody by Haemophilus influenzae

    OpenAIRE

    Clark, Sarah E.; Snow, Julian; Li, Jianjun; Zola, Tracey A.; Weiser, Jeffrey N.

    2012-01-01

    The human pathogen Haemophilus influenzae has the ability to quickly adapt to different host environments through phase variation of multiple structures on its lipooligosaccharide (LPS), including phosphorylcholine (ChoP). During colonization with H. influenzae, there is a selection for ChoP+ phase variants. In a murine model of nasopharyngeal colonization, this selection is lost in the absence of adaptive immunity. Based on previous data highlighting the importance of natural antibody in lim...

  19. Semiautomated determination of minimum bactericidal concentrations of antibiotics

    OpenAIRE

    O'grady, F.; Murphy, Barbara; Pearson, NJ

    1983-01-01

    Using a newly devised 50-channel photometer which records the opacity of growing bacterial cultures, it was shown that the time taken by cultures diluted 1/1000 in fresh broth to reach 50% of the opacity of a fully grown culture was inversely related to the concentration of organisms in the original culture. This relation was used to determine the numbers of survivors after exposure to benzylpenicillin and gentamicin alone and in combination. The procedure is commended as a labour-saving and ...

  20. Bactericidal activity of high voltage pulsed current (HVPC in vitro

    Directory of Open Access Journals (Sweden)

    Kramer, Axel

    2006-08-01

    Full Text Available The positive effect of electrical stimulation (ES on wound healing has been shown in vitro and in vivo. Based on increased blood flow, protein denaturation and stimulation of cellular defence, an antibacterial effect of ES is to be expected. Although the antibacterial effect of ES already has been demonstrated in vitro, little attention has been paid to the direct antibacterial effect of changing polarity of the applied current. The aim of this study was to investigate the antibacterial effect of positive and negative monophasic high voltage pulsed current (HVPV on typical gram positive and gram negative pathogens of chronic wounds.Using the WoundEL®-System, three gram negative (E. coli, P. aeruginosa, K. pneumoniae and three gram positive (S. aureus, S. epidermidis, E. faecium organisms were tested against positive and negative polarity HVPV. All tested organisms were significantly (P < 0.01 reduced by ES. The reduction differed significantly (P = 0.02 between positive and negative polarity, with the highest log10 RF achieved with positive polarity. Using positive polarity, the maximum RF was measured for Escherichia coli (median log10 RF 0.83; 25th percentile 0.59, 75th percentile 0.98, the lowest for Staphylococcus epidermidis (median log10 RF 0.20; 25th percentile 0.17, 75th percentile 0.24. Yet, there was no significant difference with positive ES against gram positive (P = 0.35 or gram negative (P = 0.71 organisms.

  1. Bactericidal Effect of Solar Water Disinfection under Real Sunlight Conditions▿

    Science.gov (United States)

    Boyle, M.; Sichel, C.; Fernández-Ibáñez, P.; Arias-Quiroz, G. B.; Iriarte-Puña, M.; Mercado, A.; Ubomba-Jaswa, E.; McGuigan, K. G.

    2008-01-01

    Batch solar disinfection (SODIS) inactivation kinetics are reported for suspensions in water of Campylobacter jejuni, Yersinia enterocolitica, enteropathogenic Escherichia coli, Staphylococcus epidermidis, and endospores of Bacillus subtilis, exposed to strong natural sunlight in Spain and Bolivia. The exposure time required for complete inactivation (at least 4-log-unit reduction and below the limit of detection, 17 CFU/ml) under conditions of strong natural sunlight (maximum global irradiance, ∼1,050 W m−2 ± 10 W m−2) was as follows: C. jejuni, 20 min; S. epidermidis, 45 min; enteropathogenic E. coli, 90 min; Y. enterocolitica, 150 min. Following incomplete inactivation of B. subtilis endospores after the first day, reexposure of these samples on the following day found that 4% (standard error, 3%) of the endospores remained viable after a cumulative exposure time of 16 h of strong natural sunlight. SODIS is shown to be effective against the vegetative cells of a number of emerging waterborne pathogens; however, bacterial species which are spore forming may survive this intervention process. PMID:18359829

  2. Use of titanium-based materials as bactericides

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, David T; Elvington, Mark C; Wataha, John; Chung, Whasun O; Rutherford, R. Bruce; Chan, Daniel C

    2013-10-01

    Compositions containing metal ions bound into a titanate are described which have demonstrated an ability to suppress bacterial growth of a number of organisms associated with periodontal disease and caries.

  3. Insights into the mechanism of action of bactericidal lipophosphonoxins

    Czech Academy of Sciences Publication Activity Database

    Panova, Natalya; Zborníková, Eva; Šimák, Ondřej; Krásný, Libor; Kolář, M.; Látal, T.; Seydlová, G.; Rejman, Dominik

    Praha : Institute of Organic Chemistry and Biochemistry AS CR, v. v. i, 2014 - (Hocek, M.), s. 115-118 ISBN 978-80-86241-50-0. - (Collection Symposium Series. 14). [Symposium on Chemistry of Nucleic Acid Components /16./. Český Krumlov (CZ), 08.06.2014-13.06.2014] R&D Projects: GA TA ČR TA02010035 Grant ostatní: GA ČR(CZ) GP13-18051P Institutional support: RVO:61388963 ; RVO:61388971 Keywords : lipophosphonoxins * cytotoxicity * antibiotics Subject RIV: CC - Organic Chemistry

  4. Insights into the Mechanism of Action of Bactericidal Lipophosphonoxins

    Czech Academy of Sciences Publication Activity Database

    Panova, Natalya; Zborníková, E.; Šimák, O.; Pohl, R.; Kolář, M.; Bogdanová, K.; Večeřová, R.; Seydlová, G.; Fišer, R.; Hadravová, R.; Šanderová, Hana; Vítovská, Dragana; Šiková, Michaela; Látal, T.; Lovecká, P.; Barvík, I.; Krásný, Libor; Rejman, D.

    2015-01-01

    Roč. 10, č. 12 (2015). E-ISSN 1932-6203 R&D Projects: GA TA ČR TA02010035; GA ČR(CZ) GBP305/12/G034 Institutional support: RVO:61388971 Keywords : CATIONIC STEROID ANTIBIOTICS * BACILLUS-SUBTILIS * ANTIBACTERIAL PROPERTIES Subject RIV: EE - Microbiology, Virology Impact factor: 3.234, year: 2014

  5. Insights into the Mechanism of Action of Bactericidal Lipophosphonoxins

    Czech Academy of Sciences Publication Activity Database

    Panova, Natalya; Zborníková, Eva; Šimák, Ondřej; Pohl, Radek; Kolář, M.; Bogdanová, K.; Večeřová, R.; Seydlová, G.; Fišer, R.; Hadravová, Romana; Šanderová, H.; Vítovská, D.; Šiková, M.; Látal, T.; Lovecká, P.; Barvík, I.; Krásný, L.; Rejman, Dominik

    2015-01-01

    Roč. 10, č. 12 (2015), e0145918/1-e0145918/28. E-ISSN 1932-6203 R&D Projects: GA TA ČR TA02010035 Institutional support: RVO:61388963 Keywords : cationic steroid antibiotics * Bacillus subtilis * antibacterial properties Subject RIV: CC - Organic Chemistry Impact factor: 3.234, year: 2014 http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0145918

  6. Bactericidal antibiotic-phytochemical combinations against methicillin resistant Staphylococcus aureus

    OpenAIRE

    Bhone Myint Kyaw; Shuchi arora; Chu Sing Lim

    2012-01-01

    Methicillin resistant Staphylococcus aureus (MRSA) infection is a global concern nowadays. Due to its multi-drug resistant nature, treatment with conventional antibiotics does not assure desired clinical outcomes. Therefore, there is a need to find new compounds and/or alternative methods to get arsenal against the pathogen. Combination therapies using conventional antibiotics and phytochemicals fulfill both requirements. In this study, the efficacy of different phytochemicals in combination ...

  7. Bactericidal antibiotic-phytochemical combinations against methicillin resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Bhone Myint Kyaw

    2012-09-01

    Full Text Available Methicillin resistant Staphylococcus aureus (MRSA infection is a global concern nowadays. Due to its multi-drug resistant nature, treatment with conventional antibiotics does not assure desired clinical outcomes. Therefore, there is a need to find new compounds and/or alternative methods to get arsenal against the pathogen. Combination therapies using conventional antibiotics and phytochemicals fulfill both requirements. In this study, the efficacy of different phytochemicals in combination with selected antibiotics was tested against 12 strains of S. aureus (ATCC MRSA 43300, ATCC methicillin sensitive S. aureus or MSSA 29213 and 10 MRSA clinical strains collected from National University Hospital, Singapore. Out of the six phytochemicals used, tannic acid was synergistic with fusidic acid, minocycline, cefotaxime and rifampicin against most of strains tested and additive with ofloxacin and vancomycin. Quercetin showed synergism with minocycline, fusidic acid and rifampicin against most of the strains. Gallic acid ethyl ester showed additivity against all strains in combination with all antibiotics under investigation except with vancomycin where it showed indifference effect. Eugenol, menthone and caffeic acid showed indifference results against all strains in combination with all antibiotics. Interestingly, no antagonism was observed within these interactions. Based on the fractional inhibitory concentration indices, synergistic pairs were further examined by time-kill assays to confirm the accuracy and killing rate of the combinations over time. The two methods concurred with each other with 92% accuracy and the combinatory pairs were effective throughout the 24 hours of assay. The study suggests a possible incorporation of effective phytochemicals in combination therapies for MRSA infections.

  8. Glyceryl monooleate-based otic delivery system of ofloxacin: release profile and bactericidal activity.

    Science.gov (United States)

    Adwan, Samer; Abu-Dahab, Rana; Al-Bakri, Amal G; Sallam, Alsayyed

    2015-05-01

    This study investigated the preparation and characterization of glyceryl monooleate- (GMO) based drug delivery system containing ofloxacin for the treatment of otitis externa. Acetate buffer (pH 4.5) containing dissolved ofloxacin was added to molten GMO as an aqueous phase, this resulted in the formation of a cubic and a reverse hexagonal phases. The release behavior of ofloxacin from the drug delivery system was studied using three different methods. The mechanism of drug release using paddles/dissolution apparatus and Franz diffusion cells followed Higuchi and Fickian diffusion models; whereas intrinsic release rate method showed zero-order kinetics. The intrinsic release rate was estimated and found to be 187.2 µg/cm(2)/h. The release mechanisms were similar irrespective of the loaded ofloxacin amount, however, the higher drug load displayed higher release rate. The drug delivery system was proven to be microbiologically effective by using agar diffusion method, against Staphylococcus aureus, and Pseudomonas aeruginosa. The GMO/ofloxacin formulation was stable for 6 months after preparation at room temperature as measured with respect to phase stability and antibacterial activity. PMID:24392877

  9. Bactericidal action mechanism of negatively charged food grade clove oil nanoemulsions.

    Science.gov (United States)

    Majeed, Hamid; Liu, Fei; Hategekimana, Joseph; Sharif, Hafiz Rizwan; Qi, Jing; Ali, Barkat; Bian, Yuan-Yuan; Ma, Jianguo; Yokoyama, Wallace; Zhong, Fang

    2016-04-15

    Clove oil (CO) anionic nanoemulsions were prepared with varying ratios of CO to canola oil (CA), emulsified and stabilized with purity gum ultra (PGU), a newly developed succinylated waxy maize starch. Interfacial tension measurements showed that CO acted as a co-surfactant and there was a gradual decrease in interfacial tension which favored the formation of small droplet sizes on homogenization until a critical limit (5:5% v/v CO:CA) was reached. Antimicrobial activity of the negatively charged CO nanoemulsion was determined against Gram positive GPB (Listeria monocytogenes and Staphylococcus aureus) and Gram negative GNB (Escherichia coli) bacterial strains using minimum inhibitory concentration (MIC) and a time kill dynamic method. Negatively charged PGU emulsified CO nanoemulsion showed prolonged antibacterial activities against Gram positive bacterial strains. We concluded that negatively charged CO nanoemulsion droplets self-assemble with GPB cell membrane, and facilitated interaction with cellular components of bacteria. Moreover, no electrostatic interaction existed between negatively charged droplets and the GPB membrane. PMID:26616926

  10. The Lytic SA Phage Demonstrate Bactericidal Activity against Mastitis Causing Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Hamza Ameer

    2016-04-01

    Full Text Available Staphylococcus aureus is the major causative agent of mastitis among dairy animals as it causes intramammary gland infection. Due to antibiotic resistance and contamination of antibiotics in the milk of diseased animals; alternative therapeutic agents are required to cure mastitis. Lytic bacteriophages and their gene products can be potential therapeutic agents against bacteria as they are host specific and less harmful than antibiotics. In this study, Staphylococcus aureus were isolated from milk samples of the infected animals and identified biochemically. SA phage was isolated from sewage water showing lytic activity against Staphylococcus aureus isolates. The highest lytic activity of bacteriophages was observed at 37°C and pH 7, and the most suitable storage condition was at 4°C. SA phage efficiently reduced bacterial growth in the bacterial reduction assay. The characterization and bacterial growth reduction activity of the bacteriophages against Staphylococcus aureus signifies their underlying potential of phage therapy against mastitis.

  11. Bactericidal effectiveness of UV radiators, type DRT-400, in a broilerhouse

    International Nuclear Information System (INIS)

    Three UV radiators, type DRT-400, were used in a broilerhouse of BIOS type; 12 lamps in a set, type ZNUV, worked inside of the premises for 5, 8, 12, 16 and 20 min. It was found a high degree reduction of bacteria and fungi in the air, at 60.3 and 74.0% respectively, on the external surface of bedding at 40.3% and 72.2%, and in automatic watering troughs at 44.0 and 97.7% respectively. The degree of microorganisms reduction depended on the time exposition to UV, general air contamination, place of contamination, i.e. bedding or water in troughs. (author)

  12. Laser assisted periodontal treatment: from bactericidal effect to local modification of the host response

    Science.gov (United States)

    Ciurescu, Codruţa.; Teslaru, Silvia; Zetu, Liviu; Ciurescu, Daniel

    2016-03-01

    The aim of the present short-term study is to investigate efficiency of laser therapy as adjunct to conventional periodontal therapy in patients with chronic periodontitis. Methods. The study protocol included 44 patients (20 males, 24 females; age 45-60) with moderate and advanced chronic periodontitis, recruited in Private Clinic Krondent (Brasov, Romania). The patients were randomly assigned in two groups, one group (test-sites group, 22 patients) treated by ultrasonic scaling and root planning followed by laser therapy (940 nm diode laser and 2780 nm Er:Cr:YAG laser) and second group (control-sites group, 22 patients) treated only by ultrasonic scaling and root planning. All patients were submitted to initial evaluation, recording of bleeding on probing (BOP) and probing of pockets depth (PPD), oral hygiene instruction and motivation. Indices BOP and PPD for the assessed periodontal sites were also recorded at 8 weeks, 16 weeks and 24 weeks after treatment. Results. Periodontal inflammatory parameters PPD (PPD>=4mm) were significantly lower in test-sites group as compared with control-sites group at 2 months (82% vs. 90%), 4 months (42% vs. 62%), and 6 months (11% vs. 30%).Periodontal parameters BOP were lower among patients in control-sites group and test-sites group at 2 months (38% vs. 32%), and significantly lower in test-sites group at 4 months (42% vs.26%), and 6 months (44% vs. 24%). Conclusions. The additional use of laser therapy increases significantly the efficiency of periodontal treatment comparing with conventional periodontal therapy.

  13. Bactericidal effect of lactoferrin and lactoferrin chimera against halophilic Vibrio parahaemolyticus

    NARCIS (Netherlands)

    N. Leon-Sicairos; A. Canizalez-Roman; M. de la Garza; M. Reyes-Lopez; J. Zazueta-Beltran; K. Nazmi; B. Gomez-Gil; J.G. Bolscher

    2009-01-01

    Infections caused by Vibrio parahaemolyticus, an halophilic member of the genus Vibrio, have increased globally in the last 5 years. Diarrhea caused by V. parahaemolyticus results from eating raw or undercooked seafood. The aim of this work was to investigate whether lactoferrin and some lactoferrin

  14. Two approaches to form antibacterial surface: Doping with bactericidal element and drug loading

    Czech Academy of Sciences Publication Activity Database

    Sukhoruková, I.V.; Sheveyko, A.N.; Kiryukhantsev-Korneev, Ph. V.; Anisimová, N.Y.; Gloushanková, N.A.; Zhitnyak, I.Y.; Benešová, Jana; Amler, Evžen; Shtanský, D.V.

    2015-01-01

    Roč. 330, MAR 1 (2015), s. 339-350. ISSN 0169-4332 Institutional support: RVO:68378041 Keywords : bioactive nanostructured films * antibacterial activity * cell proliferation * drug release Subject RIV: FP - Other Medical Disciplines Impact factor: 2.711, year: 2014

  15. Impact of feed spacer and membrane modification by hydrophilic, bactericidal and biocidal coating on biofouling control

    KAUST Repository

    Araújo, Paula A.

    2012-06-01

    The influence of polydopamine- and polydopamine-. graft-poly(ethylene glycol)-coated feed spacers and membranes, copper-coated feed spacers, and commercially-available biostatic feed spacers on biofouling has been studied in membrane fouling simulators. Feed spacers and membranes applied in practical membrane filtration systems were used; biofouling development was monitored by feed channel pressure drop increase and biomass accumulation. Polydopamine and polydopamine-. g-PEG are hydrophilic surface modification agents expected to resist protein and bacterial adhesion, while copper feed spacer coatings and biocides infused in feed spacers are expected to restrict biological growth. Our studies showed that polydopamine and polydopamine-. g-PEG coatings on feed spacers and membranes, copper coatings on feed spacers, and a commercial biostatic feed spacer did not have a significant impact on feed channel pressure drop increase and biofilm accumulation as measured by ATP and TOC content. The studied spacer and membrane modifications were not effective for biofouling control; it is doubtful that feed spacer and membrane modification, in general, may be effective for biofouling control regardless of the type of applied coating. © 2012 Elsevier B.V.

  16. Flexible bactericidal graphene oxide–chitosan layers for stem cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Mazaheri, M. [Department of Materials Science and Engineering, Sharif University of Technology, PO Box 11365-9466, Tehran (Iran, Islamic Republic of); Akhavan, O., E-mail: oakhavan@sharif.edu [Department of Physics, Sharif University of Technology, PO Box 11155-9161, Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, PO Box 14588-89694, Tehran (Iran, Islamic Republic of); Simchi, A. [Department of Materials Science and Engineering, Sharif University of Technology, PO Box 11365-9466, Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, PO Box 14588-89694, Tehran (Iran, Islamic Republic of)

    2014-05-01

    Highlights: • Fabrication of flexible graphene oxide–chitosan nanocomposite layers was reported. • The flexibility of the chitosan layers were improved by adding graphene oxide sheets. • The nanocomposite layers with 1.5 wt% graphene oxide content showed yielded flexible and antibacterial surfaces for stem cell proliferation. - Abstract: Graphene oxide (GO)–chitosan composite layers with stacked layer structures were synthesized using chemically exfoliated GO sheets (with lateral dimensions of ∼1 μm and thickness of ∼1 nm), and applied as antibacterial and flexible nanostructured templates for stem cell proliferation. By increasing the GO content from zero to 6 wt%, the strength and elastic modulus of the layers increased ∼80% and 45%, respectively. Similar to the chitosan layer, the GO–chitosan composite layers showed significant antibacterial activity (>77% inactivation after only 3 h) against Staphylococcus aureus bacteria. Surface density of the actin cytoskeleton fibers of human mesenchymal stem cells (hMSCs) cultured on the chitosan and GO(1.5 wt%)–chitosan composite layers was found nearly the same, while it significantly decreased by increasing the GO content to 3 and 6 wt%. Our results indicated that although a high concentration of GO in the chitosan layer (here, 6 wt%) could decelerate the proliferation of the hMSCs on the flexible layer, a low concentration of GO (i.e., 1.5 wt%) not only resulted in biocompatibility but also kept the mechanical flexibility of the self-sterilized layers for high proliferation of hMSCs.

  17. Plant-mediated synthesis of biosilver nanoparticles using Pandanus amaryllifolius extract and its bactericidal activity

    Energy Technology Data Exchange (ETDEWEB)

    Akhir, Rabiatuladawiyah Md.; Fairuzi, Afiza Ahmad [School of Physics and Material Studies, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, 40450 Selangor Darul Ehsan (Malaysia); Ismail, Nur Hilwani [School of Biology, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, 40450 Selangor Darul Ehsan Malaysia (Malaysia)

    2015-08-28

    In this work, we describe a cost effective, easily scaled up and environmental friendly technique for green synthesis of silver nanoparticles (AgNPs) from 5 mM AgNO{sub 3} solution using aqueous extract of Pandanus amaryllifolius (P. amaryllifolius) leaves as reducing agent. Biosynthesized silver nanoparticles was confirmed by sampling the reaction mixture at regular intervals and the absorption maxima was scanned by Ultraviolet-Visible (UV-Vis) spectroscopy at wavelength of 200-500 nm. Images from Field Emission Scanning Electron Microscope (FESEM) have shown that the silver nanoparticles are 17-30 nm in range and assembled in mostly spherical shape. Elemental composition analysis by using Energy Dispersive X-ray (EDX) confirmed the presence of silver. Low concentration of biosynthesized silver nanoparticles have been found to exhibit good antibacterial activity against Staphylococcus aureus bacteria with average mean diameter of zone of inhibition (ZOI) of 16 mm.

  18. THE USE OF CHEMICALS AS FUNGICIDES, BACTERICIDES AND NEMATOCIDES. AGRICULTURAL CHEMICALS TECHNOLOGY, NUMBER 4.

    Science.gov (United States)

    Ohio State Univ., Columbus. Center for Vocational and Technical Education.

    THE PURPOSE OF THIS GUIDE IS TO ASSIST TEACHERS IN PREPARING POST-SECONDARY EDUCATION STUDENTS FOR AGRICULTURAL CHEMICAL OCCUPATIONS. ONE OF A SERIES FOR THESE OCCUPATIONS, THIS MODULE WAS DEVELOPED BY A NATIONAL TASK FORCE ON THE BASIS OF DATA FROM STATE STUDIES. SECTIONS ARE (1) PLANT DISEASE AND NEMATODE PREVENTION, CONTROL, OR ERADICATION WITH…

  19. Reactive Oxygen Species Contribute to the Bactericidal Effects of the Fluoroquinolone Moxifloxacin in Streptococcus pneumoniae.

    Science.gov (United States)

    Ferrándiz, M J; Martín-Galiano, A J; Arnanz, C; Zimmerman, T; de la Campa, A G

    2016-01-01

    We studied the transcriptomic response of Streptococcus pneumoniae to the fluoroquinolone moxifloxacin at a concentration that inhibits DNA gyrase. Treatment of the wild-type strain R6, at a concentration of 10× the MIC, triggered a response involving 132 genes after 30 min of treatment. Genes from several metabolic pathways involved in the production of pyruvate were upregulated. These included 3 glycolytic enzymes, which ultimately convert fructose 6-phosphate to pyruvate, and 2 enzymes that funnel phosphate sugars into the glycolytic pathway. In addition, acetyl coenzyme A (acetyl-CoA) carboxylase was downregulated, likely leading to an increase in acetyl-CoA. When coupled with an upregulation in formate acetyltransferase, an increase in acetyl-CoA would raise the production of pyruvate. Since pyruvate is converted by pyruvate oxidase (SpxB) into hydrogen peroxide (H2O2), an increase in pyruvate would augment intracellular H2O2. Here, we confirm a 21-fold increase in the production of H2O2 and a 55-fold increase in the amount of hydroxyl radical in cultures treated during 4 h with moxifloxacin. This increase in hydroxyl radical through the Fenton reaction would damage DNA, lipids, and proteins. These reactive oxygen species contributed to the lethality of the drug, a conclusion supported by the observed protective effects of an SpxB deletion. These results support the model whereby fluoroquinolones cause redox alterations. The transcriptional response of S. pneumoniae to moxifloxacin is compared with the response to levofloxacin, an inhibitor of topoisomerase IV. Levofloxacin triggers the transcriptional activation of iron transport genes and also enhances the Fenton reaction. PMID:26525786

  20. Ability of Staphylococcus aureus coagulase genotypes to resist neutrophil bactericidal activity and phagocytosis

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Scott, N. L.; Sordillo, L. M.

    1994-01-01

    This study investigated the functional capabilities of neutrophils against different Staphylococcus aureus genotypes isolated from cows with mastitis. Six strains of S. aureus were chosen for use in the study, two with a common genotype, two with an intermediate genotype, and two with a rare.......26/cell; rare type, 10.5/cell). These findings suggest that one of the reasons for the variation in prevalence of different genotypes of S. aureus in the mammary gland is due to the superior ability of some types to resist phagocytosis and/or killing by bovine neutrophils...

  1. An alternative bactericidal mechanism of action for lantibiotic peptides that target lipid II.

    Science.gov (United States)

    Hasper, Hester E; Kramer, Naomi E; Smith, James L; Hillman, J D; Zachariah, Cherian; Kuipers, Oscar P; de Kruijff, Ben; Breukink, Eefjan

    2006-09-15

    Lantibiotics are polycyclic peptides containing unusual amino acids, which have binding specificity for bacterial cells, targeting the bacterial cell wall component lipid II to form pores and thereby lyse the cells. Yet several members of these lipid II-targeted lantibiotics are too short to be able to span the lipid bilayer and cannot form pores, but somehow they maintain their antibacterial efficacy. We describe an alternative mechanism by which members of the lantibiotic family kill Gram-positive bacteria by removing lipid II from the cell division site (or septum) and thus block cell wall synthesis. PMID:16973881

  2. An alternative bactericidal mechanism of action for lantibiotic peptides that target lipid II

    NARCIS (Netherlands)

    Hasper, Hester E.; Kramer, Naomi E.; Smith, James L.; Hillman, J. D.; Zachariah, Cherian; Kuipers, Oscar P.; de Kruijff, Ben; Breukink, Eefjan

    2006-01-01

    Lantibiotics are polycyclic peptides containing unusual amino acids, which have binding specificity for bacterial cells, targeting the bacterial cell wall component lipid II to form pores and thereby lyse the cells. Yet several members of these lipid II - targeted lantibiotics are too short to be ab

  3. Radioiodinated DPA-713 Imaging Correlates with Bactericidal Activity of Tuberculosis Treatments in Mice

    OpenAIRE

    Ordonez, Alvaro A.; Pokkali, Supriya; DeMarco, Vincent P.; Klunk, Mariah; Mease, Ronnie C.; Foss, Catherine A.; Pomper, Martin G.; Jain, Sanjay K.

    2014-01-01

    Current tools for monitoring response to tuberculosis treatments have several limitations. Noninvasive biomarkers could accelerate tuberculosis drug development and clinical studies, but to date little progress has been made in developing new imaging technologies for this application. In this study, we developed pulmonary single-photon emission computed tomography (SPECT) using radioiodinated DPA-713 to serially monitor the activity of tuberculosis treatments in live mice, which develop necro...

  4. BACTERICIDAL EFFECTS OF VARIOUS IRRIGATION SOLUTIONS AGAINST STAPHYLOCOCCUS AUREUS IN HUMAN ROOT CANAL

    Directory of Open Access Journals (Sweden)

    Recai Zan

    2015-01-01

    Full Text Available Purpose: The aim of the present study was to evaluate and to compare the antibacterial effects of various irrigation solutions against Staphylococcus aureus (S. aureus in human root canals. Materials and Methods: 120 single-root mandibular premolar teeth were selected. The teeth were prepared and sterilized. S. aureus was incubated in the root canals and kept at 37°C for 24h. The infected root canals were divided into one positive (saline and one negative (sodium hypochlorite control, and four experimental groups [Ethylene-diaminetetra-aceticacid, Chlorhexidine Gluconate, Super-oxidized water(SPO, Aqueous ozone] (n=20. Flow rate of irrigation was applied with 5 mL/min flow rate for 3 min to ensure standardization among all study groups. Following the irrigation, paper points were placed in the root canals and then transferred in sterile eppendorf. Remaining bacteria were counted on blood agar plates and the data were analyzed using one-way ANOVA and Tukey’s test. Results: Although there were statistically significant differences among SPO and other experimental groups (p0.05. Conclusion: Super-oxidized water may be recommended as an alternative irrigation solution instead of NaOCl against S. aureus in root canals.

  5. Probing bactericidal mechanisms induced by cold atmospheric plasmas with Escherichia coli mutants

    International Nuclear Information System (INIS)

    Mechanisms of plasma-induced microbial inactivation have commonly been studied with physicochemical techniques. In this letter, Escherichia coli K-12 and its ΔrecA, ΔrpoS, and ΔsoxS mutants are employed to discriminate effects of UV photons, OH radicals, and reactive oxygen species produced in atmospheric discharges. This microbiological approach exploits the fact that these E. coli mutants are defective in their resistance against various external stresses. By interplaying bacterial inactivation kinetics with optical emission spectroscopy, oxygen atoms are identified as a major contributor in plasma inactivation with minor contributions from UV photons, OH radicals, singlet oxygen metastables, and nitric oxide

  6. Dye adsorption and bactericidal properties of TiO2/chitosan coating layer.

    Science.gov (United States)

    Kamal, Tahseen; Anwar, Yasir; Khan, Sher Bahadar; Chani, Muhammad Tariq Saeed; Asiri, Abdullah M

    2016-09-01

    A new kind of titanium oxide dispersed in chitosan (TiO2/CS) nanocomposite adsorbent was prepared and adhered to high surface area substrate, cellulose microfibers mat (CMM). CS-CMM and TiO2/CS-CMM were used for the thymol violet (TV) dye removal from wastewater. Characterization of materials was carried out by X-ray diffraction, scanning electron microscope and energy dispersive X-ray spectroscopy. The adsorption properties of both the CS-CMM and TiO2/CS-CMM were investigated as a function of adsorbent dosage, solution pH, and contact time. It was revealed that the composites pretreated in the solution with higher pH value exhibited larger adsorption capacities. Kinetic studies showed that the composites could adsorb TV dye rapidly and reached the equilibrium in 90min. The adsorption process followed pseudo-second order kinetics and involved particle diffusion mechanism. The calculated maximum adsorption capacities of CS-CMM and TiO2/CS-CMM were 84.32 and 97.51mgg(-1), respectively. Compare to CS, the TiO2/CS nanocomposite coated CMM showed higher antibacterial characteristics as tested against Escherichia coli. PMID:27185126

  7. Bactericidal and Fungicidal Activity in the Gas Phase of Sodium Dichloroisocyanurate (NaDCC).

    Science.gov (United States)

    Proto, Antonio; Zarrella, Ilaria; Cucciniello, Raffaele; Pironti, Concetta; De Caro, Francesco; Motta, Oriana

    2016-08-01

    Sodium dichloroisocyanurate (NaDCC) is usually employed as a disinfectant for the treatment of water, environmental surfaces and medical equipment principally for its effectiveness as a microbicide agent. In this study, we explore the possibility of a new use for NaDCC by investigating the microbicidal activity of chlorine, which derives from the hydrolysis of NaDCC mediated by air humidity, and by testing its effect on the neutralization of microbes present in domestic waste. NaDCC was inserted in a plastic garbage can where LB agar plates, with different dilutions of a known title of four different microorganisms (Escherichia coli, Staphylococcus aureus, Debaryomyces hansenii and Aspergillus brasiliensis), were weakly inserted. The molecular chlorine (Cl2) levels present in the garbage can were quantified using an iodometric titration. The gas emitted in the garbage can presented a strong microbicide effect, inhibiting the proliferation of all four microorganisms and for four consecutive weeks, thus showing that NaDCC hydrolysis, mediated by air humidity, is able to ensure the decontamination of restricted environments, avoiding the proliferation of both Gram-positive and Gram-negative bacteria as well as fungi. PMID:27086304

  8. Roles of antibody and complement in the bactericidal activity of mouse peritoneal exudate neutrophils.

    OpenAIRE

    Hart, P. H.; Spencer, L. K.; Hill, N L; McDonald, P J; Finlay-Jones, J. J.

    1987-01-01

    The contributions of complement and antibody to phagocytosis and, as a separate process, intracellular killing of Proteus mirabilis, were investigated using mouse peritoneal exudate neutrophils. Phagocytosis of P. mirabilis was promoted by both immune mouse (IMS) and normal mouse (NMS) sera. Opsonization by IMS promoted significantly greater phagocytosis than did NMS, as did NMS compared with heated IMS (HIMS). The ability of NMS to opsonize P. mirabilis for both phagocytosis and phagocytic k...

  9. Silver nanoparticles strongly enhance and restore bactericidal activity of inactive antibiotics against multiresistant Enterobacteriaceae.

    Science.gov (United States)

    Panáček, Aleš; Smékalová, Monika; Večeřová, Renata; Bogdanová, Kateřina; Röderová, Magdaléna; Kolář, Milan; Kilianová, Martina; Hradilová, Šárka; Froning, Jens P; Havrdová, Markéta; Prucek, Robert; Zbořil, Radek; Kvítek, Libor

    2016-06-01

    Bacterial resistance to conventional antibiotics is currently one of the most important healthcare issues, and has serious negative impacts on medical practice. This study presents a potential solution to this problem, using the strong synergistic effects of antibiotics combined with silver nanoparticles (NPs). Silver NPs inhibit bacterial growth via a multilevel mode of antibacterial action at concentrations ranging from a few ppm to tens of ppm. Silver NPs strongly enhanced antibacterial activity against multiresistant, β-lactamase and carbapenemase-producing Enterobacteriaceae when combined with the following antibiotics: cefotaxime, ceftazidime, meropenem, ciprofloxacin and gentamicin. All the antibiotics, when combined with silver NPs, showed enhanced antibacterial activity at concentrations far below the minimum inhibitory concentrations (tenths to hundredths of one ppm) of individual antibiotics and silver NPs. The enhanced activity of antibiotics combined with silver NPs, especially meropenem, was weaker against non-resistant bacteria than against resistant bacteria. The double disk synergy test showed that bacteria produced no β-lactamase when treated with antibiotics combined with silver NPs. Low silver concentrations were required for effective enhancement of antibacterial activity against multiresistant bacteria. These low silver concentrations showed no cytotoxic effect towards mammalian cells, an important feature for potential medical applications. PMID:26970828

  10. Nano-structured and functionalized surfaces for cytocompatibility improvement and bactericidal action

    Czech Academy of Sciences Publication Activity Database

    Slepička, P.; Kasálková-Slepičková, N.; Siegel, J.; Kolská, Z.; Bačáková, Lucie; Švorčík, V.

    2015-01-01

    Roč. 33, 6 Part 2 (2015), s. 1120-1129. ISSN 0734-9750 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:67985823 Keywords : polymers * surface modification * cell-material interaction * tissue engineering Subject RIV: JJ - Other Materials Impact factor: 9.015, year: 2014

  11. Flexible bactericidal graphene oxide–chitosan layers for stem cell proliferation

    International Nuclear Information System (INIS)

    Highlights: • Fabrication of flexible graphene oxide–chitosan nanocomposite layers was reported. • The flexibility of the chitosan layers were improved by adding graphene oxide sheets. • The nanocomposite layers with 1.5 wt% graphene oxide content showed yielded flexible and antibacterial surfaces for stem cell proliferation. - Abstract: Graphene oxide (GO)–chitosan composite layers with stacked layer structures were synthesized using chemically exfoliated GO sheets (with lateral dimensions of ∼1 μm and thickness of ∼1 nm), and applied as antibacterial and flexible nanostructured templates for stem cell proliferation. By increasing the GO content from zero to 6 wt%, the strength and elastic modulus of the layers increased ∼80% and 45%, respectively. Similar to the chitosan layer, the GO–chitosan composite layers showed significant antibacterial activity (>77% inactivation after only 3 h) against Staphylococcus aureus bacteria. Surface density of the actin cytoskeleton fibers of human mesenchymal stem cells (hMSCs) cultured on the chitosan and GO(1.5 wt%)–chitosan composite layers was found nearly the same, while it significantly decreased by increasing the GO content to 3 and 6 wt%. Our results indicated that although a high concentration of GO in the chitosan layer (here, 6 wt%) could decelerate the proliferation of the hMSCs on the flexible layer, a low concentration of GO (i.e., 1.5 wt%) not only resulted in biocompatibility but also kept the mechanical flexibility of the self-sterilized layers for high proliferation of hMSCs

  12. BACTERICIDE IMPACT OF POLYMER-STABILIZED MULTI-FUNCTIONAL NANO-COMPOSITES

    Directory of Open Access Journals (Sweden)

    Graskova I.A.

    2012-08-01

    Full Text Available Synthesis on the basis of natural matrices in order to acquire products with the desired properties is one of the promising trends of modern science. Using polysaccharides as a matrix allowed to generate derivatives with diverse structures and new properties. Growing interest towards anti-microbe effect of selenium-containing nano-composites is induced by the phenomenon of antibiotic-resistance of contemporary pathogenic microorganisms.Clavibacter genus bacteria are the most significant and widely spread among gram-positive bacteria. Bacteria cells are static pleimorphous rods, normally singular, sometimes coupled or joined in short chains, strict anaerobes in need of certain growth factors, non-sporogenous. Clavibacter michiganensis subsp. sepedonicus cause potato ring rot. At the tuber slice the damage is shaped as a ring; growing bacteria are accumulated in the conducting vessels causing their occlusion and therefore gradual withering of leaves and stem. This disease is distributed at all the continents including Australia. Harvest loss through ring rot damage may reach 10-45%.Our work was aimed at the study of complex interaction between microbe cultivar and selenium-based nanocomposites. Bacterial strain Аs1405 was acquired from the All-Russia collection of microorganisms, IMBP RAS. This genus is not included in the classification of pathogenic microorganisms by pathogenic groups of Sanitary-Epidemiological Rules SP 1.3.2322-08. The present study was focused on characteristics of the acquired strain.Fluorescent and electronic-scanning microscope was used to acquire photographs of bacterial cells. Pathogen was identified by PCR-analysis, which confirmed the presence of DNA of desired size. The extracted DNA was sequenced with the sequenced sequence added to Gen Bank under the number HQ394204. Cellulolytic and phytotoxic activity of this strain was determined.Chemistry Institute named A.E. Favorsky provided water-soluble nano-composites containing selenium stabilized by various polymers. Nano-composites anti-microbe activity was studied on the investigated strain of potato ring rot. Nano-composites of elementary selenium (3.4% Se and Se with arabinogalactan acquired from SeO2 (1.23% Se were found to demonstrate anti-microbe effect increasing with the rise of selenium content. The work enumerates various conditions and time periods of cultivation and determination of the influence of the given water-soluble nano-composites on bacterial cells survivability.

  13. Re-Examining the Role of Hydrogen Peroxide in Bacteriostatic and Bactericidal Activities of Honey

    OpenAIRE

    Brudzynski, Katrina; Abubaker, Kamal; St-Martin, Laurent; Castle, Alan

    2011-01-01

    The aim of this study was to critically analyze the effects of hydrogen peroxide on growth and survival of bacterial cells in order to prove or disprove its purported role as a main component responsible for the antibacterial activity of honey. Using the sensitive peroxide/peroxidase assay, broth microdilution assay and DNA degradation assays, the quantitative relationships between the content of H2O2 and honey’s antibacterial activity was established. The results showed that: (A) the average...

  14. Bactericidal activity of green tea extracts: the importance of catechin containing nano particles

    OpenAIRE

    Judy Gopal; Manikandan Muthu; Diby Paul; Doo-Hwan Kim; Sechul Chun

    2016-01-01

    When we drink green tea infusion, we believe we are drinking the extract of the green tea leaves. While practically each tea bag infused in 300 mL water contains about 50 mg of suspended green tea leaf particles. What is the role of these particles in the green tea effect is the objective of this study. These particles (three different size ranges) were isolated via varying speed centrifugation and their respective inputs evaluated. Live oral bacterial samples from human volunteers have been ...

  15. Bactericidal effect of hydrolysable and condensed tannin extracts on Campylobacter jejuni in vitro.

    Science.gov (United States)

    Anderson, Robin C; Vodovnik, Maša; Min, Byeng R; Pinchak, William E; Krueger, Nathan A; Harvey, Roger B; Nisbet, David J

    2012-07-01

    Strategies are sought to reduce intestinal colonisation of food-producing animals by Campylobacter jejuni, a leading bacterial cause of human foodborne illness worldwide. Presently, we tested the antimicrobial activity of hydrolysable-rich blackberry, cranberry and chestnut tannin extracts and condensed tannin-rich mimosa, quebracho and sorghum tannins (each at 100 mg/mL) against C. jejuni via disc diffusion assay in the presence of supplemental casamino acids. We found that when compared to non-tannin-treated controls, all tested tannins inhibited the growth of C. jejuni and that inhibition by the condensed tannin-rich mimosa and quebracho extracts was mitigated in nutrient-limited medium supplemented with casamino acids. When tested in broth culture, both chestnut and mimosa extracts inhibited growth of C. jejuni and this inhibition was much greater in nutrient-limited than in full-strength medium. Consistent with observations from the disc diffusion assay, the inhibitory activity of the condensed tannin-rich mimosa extracts but not the hydrolysable tannin-rich chestnut extracts was mitigated by casamino acid supplementation to the nutrient-limited medium, likely because the added amino acids saturated the binding potential of the condensed tannins. These results demonstrate the antimicrobial activity of various hydrolysable and condensed tannin-rich extracts against C. jejuni and reveal that condensed tannins may be less efficient than hydrolysable tannins in controlling C. jejuni in gut environments containing high concentrations of amino acids and soluble proteins. PMID:22528299

  16. Monoclonal antibodies against the iron regulated outer membrane Proteins of Acinetobacter baumannii are bactericidal

    OpenAIRE

    Goel, Vikas Kumar; Kapil, Arti

    2001-01-01

    Background Iron is an important nutrient required by all forms of life.In the case of human hosts,the free iron availability is 10-18M,which is far less than what is needed for the survival of the invading bacterial pathogen.To survive in such conditions, bacteria express new proteins in their outer membrane and also secrete iron chelators called siderophores. Results/ Discussion Acinetobacter baumannii ATCC 19606, a nosocomial pathogen which grows under iron restricted conditions, expresses ...

  17. Bactericidal Effects of Natural Tenderizing Enzymes on Escherichia Coli and Listeria monocytogenes

    OpenAIRE

    Hanan Eshamah; Inyee Han; Hesham Naas; James Rieck; Paul Dawson

    2012-01-01

    The objective of this study was to determine the antimicrobial activity of proteolytic, meat-tenderizing enzymes (papain and bromelain) against E. coli and L. monocytogenes at three different temperatures (5, 25 and 35°C). Two overnight cultures of E. coli JM109 and L. monocytogenes were separately suspended in 1% peptone water and exposed to a proteolytic enzyme (papain or bromelain) at three different temperatures. Bromelain concentrations (4 mg/ml) and (1 mg/ml) tested at 25°C against E. c...

  18. Effect of dexamethasone on bactericidal activity of turkey monocytes and implications for food safety

    Science.gov (United States)

    Stress has been shown to affect the immune system of turkeys making them more susceptible to bacterial infections that may compromise food safety. Female turkeys are more resistant to stress-induced opportunistic bacterial infections than are male turkeys. In order to determine the mechanism of this...

  19. Plant-mediated synthesis of biosilver nanoparticles using Pandanus amaryllifolius extract and its bactericidal activity

    International Nuclear Information System (INIS)

    In this work, we describe a cost effective, easily scaled up and environmental friendly technique for green synthesis of silver nanoparticles (AgNPs) from 5 mM AgNO3 solution using aqueous extract of Pandanus amaryllifolius (P. amaryllifolius) leaves as reducing agent. Biosynthesized silver nanoparticles was confirmed by sampling the reaction mixture at regular intervals and the absorption maxima was scanned by Ultraviolet-Visible (UV-Vis) spectroscopy at wavelength of 200-500 nm. Images from Field Emission Scanning Electron Microscope (FESEM) have shown that the silver nanoparticles are 17-30 nm in range and assembled in mostly spherical shape. Elemental composition analysis by using Energy Dispersive X-ray (EDX) confirmed the presence of silver. Low concentration of biosynthesized silver nanoparticles have been found to exhibit good antibacterial activity against Staphylococcus aureus bacteria with average mean diameter of zone of inhibition (ZOI) of 16 mm

  20. Synthesis and evaluation of bactericidal properties of CuO nanoparticles against Aeromonas hydrophila

    OpenAIRE

    Sayedeh Fatemeh Shaffiey; Sayed Reza Shaffiey; Mohammad Ahmadi; Farshid Azari

    2014-01-01

      Objective(s): CuO is one of the most important transition metal oxides due to its captivating properties. It is used in various technological applications such as high critical temperature superconductors, gas sensors, in photoconductive applications, and so on. Recently, it has been used as an antimicrobial agent against various bacterial species.   Materials and Methods: Here, we synthesized CuO nanoparticles (NPs) and explored the antibacterial activity of CuO NPs preparation. Results: S...

  1. Raman tweezers on bacteria: following the mechanisms of bacteriostatic versus bactericidal action

    Czech Academy of Sciences Publication Activity Database

    Bernatová, Silvie; Samek, Ota; Pilát, Zdeněk; Šerý, Mojmír; Ježek, Jan; Jákl, Petr; Šiler, Martin; Krzyžánek, Vladislav; Zemánek, Pavel; Holá, V.; Dvořáčková, M.; Růžička, F.

    Bellingham: SPIE, 2014, 91291Y:1-7. ISBN 9781628410778. ISSN 0277-786X. [Biophotonics: Photonic Solutions for Better Health Care /4./. Brussels (BE), 14.04.2014-17.04.2014] R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01; GA ČR GAP205/11/1687 Institutional support: RVO:68081731 Keywords : bacteria * microorganisms * principal component analysisp * Raman scattering Subject RIV: BH - Optics, Masers, Lasers

  2. Bactericidal Effects of Charged Silver Nanoparticles in Methicillin-resistant Staphylococcus aureus

    Science.gov (United States)

    Romero-Urbina, Dulce; Velazquez-Salazar, J. Jesus; Lara, Humberto H.; Arellano-Jimenez, Josefina; Larios, Eduardo; Yuan, Tony T.; Hwang, Yoon; Desilva, Mauris N.; Jose-Yacaman, Miguel

    2015-03-01

    The increased number of infections due to antibiotic-resistant bacteria is a major concern to society. The objective of this work is to determine the effect of positively charged AgNPs on methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus(MRSA) cell wall using advanced electron microscopy techniques. Positively charged AgNPs suspensions were synthesized via a microwave heating technique. The suspensions were then characterized by Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM) showing AgNPs size range from 5 to 30 nm. MSSA and MRSA were treated with positively charged AgNPs concentrations ranging from 0.06 mM to 31 mM. The MIC50 studies showed that viability of MSSA and MRSA could be reduced by 50% at a positively charged AgNPs concentration of 0.12 mM supported by Scanning-TEM (STEM) images demonstrating bacteria cell wall disruption leading to lysis after treatment with AgNPs. The results provide insights into one mechanism in which positively charged AgNPs are able to reduce the viability of MSSA and MRSA. This research is supported by National Institute on Minority Health and Health Disparities (G12MD007591) from NIH, NSF-PREM Grant No. DMR-0934218, The Welch Foundation and NAMRU-SA work number G1009.

  3. Lipopolysaccharide induction of autophagy is associated with enhanced bactericidal activity in Dictyostelium discoideum

    OpenAIRE

    Pflaum, Katherine; Gerdes, Kimberly; Yovo, Kossi; Callahan, Jennifer; Snyder, Michelle L.D.

    2012-01-01

    Innate immune cells respond to microbial invaders using pattern recognition receptors that detect conserved microbial patterns. Among the cellular processes stimulated downstream of pattern recognition machinery is the initiation of autophagy, which plays protective roles against intracellular microbes. We have shown recently that Dictyostelium discoideum, which takes up bacteria for nutritive purposes, may employ pattern recognition machinery to respond to bacterial prey, as D. discoideum ce...

  4. Synthesis of poly(amidoamine)-dendrimer-silver nanoparticles composite for application as bactericides

    OpenAIRE

    Shahla Namazkar; Salasiah Endud; Zohreh Asadollahi

    2014-01-01

    As awareness of sanitation, disease transmission factors and personal protection increases, researchers have focused on developing materials with antibacterial properties. Silver-PAMAM-dendrimer has unique antibacterial properties that make it an ideal candidate for medical applications. In this study, poly (amidoamine) (PAMAM) dendrimers from Generations 0.5- 4.0 were synthesized using divergent methods. Silver was combined with PAMAM dendrimers from the Generation 2.0, 3.0 and 4.0 to form c...

  5. Glucocorticoid-Augmented Efferocytosis Inhibits Pulmonary Pneumococcal Clearance in Mice by Reducing Alveolar Macrophage Bactericidal Function.

    Science.gov (United States)

    Stolberg, Valerie R; McCubbrey, Alexandra L; Freeman, Christine M; Brown, Jeanette P; Crudgington, Sean W; Taitano, Sophina H; Saxton, Bridget L; Mancuso, Peter; Curtis, Jeffrey L

    2015-07-01

    Inhaled corticosteroids (ICS) increase community-acquired pneumonia (CAP) incidence in patients with chronic obstructive pulmonary disease (COPD) by unknown mechanisms. Apoptosis is increased in the lungs of COPD patients. Uptake of apoptotic cells (ACs) ("efferocytosis") by alveolar macrophages (AMøs) reduces their ability to combat microbes, including Streptococcus pneumoniae, the most common cause of CAP in COPD patients. Having shown that ICS significantly increase AMø efferocytosis, we hypothesized that this process, termed glucocorticoid-augmented efferocytosis, might explain the association of CAP with ICS therapy in COPD. To test this hypothesis, we studied the effects of fluticasone, AC, or both on AMøs of C57BL/6 mice in vitro and in an established model of pneumococcal pneumonia. Fluticasone plus AC significantly reduced TLR4-stimulated AMø IL-12 production, relative to either treatment alone, and decreased TNF-α, CCL3, CCL5, and keratinocyte-derived chemoattractant/CXCL1, relative to AC. Mice treated with fluticasone plus AC before infection with viable pneumococci developed significantly more lung CFUs at 48 h. However, none of the pretreatments altered inflammatory cell recruitment to the lungs at 48 h postinfection, and fluticasone plus AC less markedly reduced in vitro mediator production to heat-killed pneumococci. Fluticasone plus AC significantly reduced in vitro AMø killing of pneumococci, relative to other conditions, in part by delaying phagolysosome acidification without affecting production of reactive oxygen or nitrogen species. These results support glucocorticoid-augmented efferocytosis as a potential explanation for the epidemiological association of ICS therapy of COPD patients with increased risk for CAP, and establish murine experimental models to dissect underlying molecular mechanisms. PMID:25987742

  6. Ability of Staphylococcus aureus coagulase genotypes to resist neutrophil bactericidal activity and phagocytosis

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Scott, N. L.; Sordillo, L. M.

    1994-01-01

    This study investigated the functional capabilities of neutrophils against different Staphylococcus aureus genotypes isolated from cows with mastitis. Six strains of S. aureus were chosen for use in the study, two with a common genotype, two with an intermediate genotype, and two with a rare......; rare type, 10.5/cell). These findings suggest that one of the reasons for the variation in prevalence of different genotypes of S. aureus in the mammary gland is due to the superior ability of some types to resist phagocytosis and/or killing by bovine neutrophils...

  7. Graphene Oxide Quantum Dots Covalently Functionalized PVDF Membrane with Significantly-Enhanced Bactericidal and Antibiofouling Performances

    Science.gov (United States)

    Zeng, Zhiping; Yu, Dingshan; He, Ziming; Liu, Jing; Xiao, Fang-Xing; Zhang, Yan; Wang, Rong; Bhattacharyya, Dibakar; Tan, Timothy Thatt Yang

    2016-02-01

    Covalent bonding of graphene oxide quantum dots (GOQDs) onto amino modified polyvinylidene fluoride (PVDF) membrane has generated a new type of nano-carbon functionalized membrane with significantly enhanced antibacterial and antibiofouling properties. A continuous filtration test using E. coli containing feedwater shows that the relative flux drop over GOQDs modified PVDF is 23%, which is significantly lower than those over pristine PVDF (86%) and GO-sheet modified PVDF (62%) after 10 h of filtration. The presence of GOQD coating layer effectively inactivates E. coli and S. aureus cells, and prevents the biofilm formation on the membrane surface, producing excellent antimicrobial activity and potentially antibiofouling capability, more superior than those of previously reported two-dimensional GO sheets and one-dimensional CNTs modified membranes. The distinctive antimicrobial and antibiofouling performances could be attributed to the unique structure and uniform dispersion of GOQDs, enabling the exposure of a larger fraction of active edges and facilitating the formation of oxidation stress. Furthermore, GOQDs modified membrane possesses satisfying long-term stability and durability due to the strong covalent interaction between PVDF and GOQDs. This study opens up a new synthetic avenue in the fabrication of efficient surface-functionalized polymer membranes for potential waste water treatment and biomolecules separation.

  8. Bactericidal activity of curcumin I is associated with damaging of bacterial membrane.

    Directory of Open Access Journals (Sweden)

    Poonam Tyagi

    Full Text Available Curcumin, an important constituent of turmeric, is known for various biological activities, primarily due to its antioxidant mechanism. The present study focused on the antibacterial activity of curcumin I, a significant component of commercial curcumin, against four genera of bacteria, including those that are Gram-positive (Staphylococcus aureus and Enterococcus faecalis and Gram-negative (Escherichia coli and Pseudomonas aeruginosa. These represent prominent human pathogens, particularly in hospital settings. Our study shows the strong antibacterial potential of curcumin I against all the tested bacteria from Gram-positive as well as Gram-negative groups. The integrity of the bacterial membrane was checked using two differential permeabilization indicating fluorescent probes, namely, propidium iodide and calcein. Both the membrane permeabilization assays confirmed membrane leakage in Gram-negative and Gram-positive bacteria on exposure to curcumin I. In addition, scanning electron microscopy and fluorescence microscopy were employed to confirm the membrane damages in bacterial cells on exposure to curcumin I. The present study confirms the broad-spectrum antibacterial nature of curcumin I, and its membrane damaging property. Findings from this study could provide impetus for further research on curcumin I regarding its antibiotic potential against rapidly emerging bacterial pathogens.

  9. Effects of a bactericide on the structure and survival of benthic diatom communities

    OpenAIRE

    Morin, S.; Proia, L.; Ricart, M.; Bonnineau, C.; Geiszinger, A.; Ricciardi, F.; Guasch, H.; Romani, A.M.; Sabater, S.

    2010-01-01

    We studied the adverse effects of triclosan, a widely used biocide commonly reported in surface waters, on the structure and function of benthic diatom communities. Laboratory-grown biofilms were exposed (i) to chronic contamination by increasing concentrations of triclosan and (ii) to a short-pulse of sublethal triclosan concentrations followed by a 2-week recuperation period. The first experiment was performed using 6 nominal concentrations ranging from 0.05 to 500 µg/L triclosan to obtain ...

  10. Heteronanostructure of Ag particle on titanate nanowire membrane with enhanced photocatalytic properties and bactericidal activities

    International Nuclear Information System (INIS)

    A novel seed induced method has been developed for syntheses of Ag particles on titanate nanowires, and then the heteronanostructured Ag/titanate nanowires were assembled into porous, flexible membranes. These titanate nanowires were about several hundreds micrometers in length and about 80 nm in diameter. The size of the Ag particle can be tuned within 300-700 nm. The pore size and thickness of the heteronanostructured membrane were easily controlled. An Ag/titanate nanowire membrane reactor has been developed to study the photocatalytic degradation of methamidophos in aqueous solution, and 87.0% of the methamidophos can be degraded in a concurrent filtration and photocatalytic oxidation process. The antibacterial activity was also investigated on the heteronanostructured membrane with UVA light (365 nm) irradiation, and a 99.99% satisfactory antibacterial effect on Escherichia coli was achieved.

  11. Reclamation Of Plant Wastes (Straw And Obtaining (Nano Chips With Bactericidal Properties Based On Them

    Directory of Open Access Journals (Sweden)

    Leonidovna Voropaeva Nadezda

    2015-09-01

    Full Text Available Rape, camelina, wheat and Jerusalem artichoke vegetable wastes (straw as annually renewable raw materials were processed into activated carbons, which were modified with silver nanoparticles for carbonaceous sorbents to acquire specific properties, since carbonaceous sorbents are usually widely used in the food industry, agriculture, medicine and other fields of human activity. The technology to obtain active carbons from agricultural crop residues has been developed, active carbon physico-chemical and adsorption properties, textural characteristics have been studied, new functional carbon (nano materials with antibacterial activity containing (nano particles of silver have been obtained, their influence within (nano chip composition on rape crop growth, development and yield has been studied. In the conducted field tests, the highest activity was noted when using the (nano chip whose structure included RAC - camelina and silver nanoparticles. Besides, when nano chips are used for seed treatment, the yield increase makes up 11.6 % for nanoparticles containing Ag, for plant active carbons (PAC (rape with Ag this index makes up 28.1 %, for RAC (Camelina with Ag it makes up 55.8 % (compared to the control variant, which can be explained by the differences in the sorption characteristics of the studied radio activated carbons. Our results and the previous studies of other authors can prove the fact that silver nanoparticles (including those being a part of (nano chips “get” into the biochemical processes and have a pronounced phytostimulating effect on plants, which was especially obvious when suppressing the activity of plant pathogenic microflora by silver nanoparticles.

  12. Reclamation Of Plant Wastes (Straw) And Obtaining (Nano) Chips With Bactericidal Properties Based On Them

    OpenAIRE

    Leonidovna Voropaeva Nadezda; Mukhin Viktor Mikhailovich; Anatolyevna Revina Alexandra; Alekseevich Busev Sergey; Vladimirovich Karpachev Vladimir

    2015-01-01

    Rape, camelina, wheat and Jerusalem artichoke vegetable wastes (straw) as annually renewable raw materials were processed into activated carbons, which were modified with silver nanoparticles for carbonaceous sorbents to acquire specific properties, since carbonaceous sorbents are usually widely used in the food industry, agriculture, medicine and other fields of human activity. The technology to obtain active carbons from agricultural crop residues has been developed, active carbon physico-c...

  13. Investigation of the mutagenic potential of cold atmospheric plasma at bactericidal dosages.

    Science.gov (United States)

    Boxhammer, V; Li, Y F; Köritzer, J; Shimizu, T; Maisch, T; Thomas, H M; Schlegel, J; Morfill, G E; Zimmermann, J L

    2013-04-30

    In the past few years, cold atmospheric plasma (CAP) has evolved into a new tool in the fight against nosocomial infections and antibiotic-resistant microorganisms. The products generated by the plasma-electrons, ions, reactive species and UV light-represent a 'lethal cocktail' for different kinds of pathogen, which opens up possible applications in hygiene and medicine. Nevertheless, to ensure the safe usage of CAP on skin (e.g., to treat wounds or skin diseases) several pre-clinical in vitro studies have to be performed before implementing clinical trials on humans. In the study presented here, inactivation experiments with Escherichia coli were carried out to identify the necessary plasma dosage for a 5 log reduction: with a small hand-held battery-operated CAP device, these disinfection properties were achieved after application during 30s. This and higher plasma dosages were then used to analyze the mutagenicity induced in V79 Chinese hamster cells-to furthermore define a 'safe application window'-with the HPRT (hypoxanthine-guanine phosphoribosyl transferase) mutation assay. The results show that a CAP treatment of up to 240 s and repeated treatments of 30s every 12h did not induce mutagenicity at the Hprt locus beyond naturally occurring spontaneous mutations. PMID:23416235

  14. Screening bactericidal effect of Pectobacterium carotovorum subsp. carotovorum strains against causal agent of potato soft rot.

    Science.gov (United States)

    Kazemi-Zaromi, Samaneh; Baghaee-Ravari, Sareh; Khodaygan, Pejman; Falahati-Rastegar, Mahrokh

    2016-02-01

    This study focuses on the potential of Pectobacterium carotovorum subsp. carotovorum (Pcc) strains producing bacteriocin as a tool to control potato soft rot disease. Thirty out of 48 purified bacterial strains were characterized as Pcc using specific PCR and phenotypic tests. The pathogenicity and pectate degrading assays were recorded positive for 13 strains. Bacteriocin typing clustered producers into three groups according to their antimicrobial spectra. Majority of the producers except strains of group II showed antibacterial activity toward relative genus and the role of UV or mitomycin C was inductive. In addition, none of the distant genus was sensitive to Pcc bacteriocins except Rhizobium vitis. Molecular detection of four bacteriocins including carotovoricin, carosin S1, S2 and carosin D was performed. Overall, 54.5% of group I, 47.3 and 70% of groups II and III strains carried carotovoricin and four strains harbored gene corresponding to carosin S1. According to our data divers antimicrobial patterns obtained by Pcc strains and existence of new bateriocines could be possible. Moreover, our findings recommended that direct application of P29 or expression of corresponding genes of Pog22 or P21 in a nonpathogenic strain as a biocontrol agent may improve soft rot disease control. PMID:26523939

  15. Effectivity of bactericides for oil field waters and chemicals in the secondary and tertiary petroleum production

    Energy Technology Data Exchange (ETDEWEB)

    Naeveke, R.; Schwartz, W.

    1983-06-01

    Populations of microorganisms in the petroleum area (production plants, processing plants) have been analyzed more or less extensively with respect to their components (physiologically defined groups, taxa). The by far most of the microorganisms to be found in the produced reservoir waters and petroleum are not to be regarded as autochtone microorganisms of the petroleum reservoirs. Polymers used in the viscosity flooding (hydroxy ethyl cellulose, xanthane and polyacrylamide preparations) proved to be differently resistant toward microbial attack. Xanthanes were degraded more easily, polyacrylamide was resistant. Particularly accumulative cultures of desulfurizers have proved aggressive toward polymers under anaerobic conditions. The minimal inhibiting concentrations of 9 biocides proposed to protect the polymers in the viscosity flooding were determined by 18 of these desulfurizer accumulative cultures. The values were between 10 to about 1500 g/l.

  16. Bactericidal Activity of Rifampin-Amikacin against Mycobacterium ulcerans in Mice

    OpenAIRE

    Dega, Herve; Bentoucha, Abdelhalim; Robert, Jerome; Jarlier, Vincent; Grosset, Jacques

    2002-01-01

    To identify the most active curative treatment of Buruli ulcer, two regimens incorporating the use of rifampin (RIF) were compared with the use of RIF alone in a mouse footpad model of Mycobacterium ulcerans infection. Treatments began after footpad swelling from infection and continued for 12 weeks with five doses weekly of one of the following regimens: (i) 10 mg of RIF/kg alone; (ii) 10 mg of RIF/kg and 100 mg of amikacin (AMK)/kg; and (iii) 10 mg of RIF/kg, 100 mg of clarithromycin (CLR)/...

  17. Meningococcal Serogroup B Bivalent rLP2086 Vaccine Elicits Broad and Robust Serum Bactericidal Responses in Healthy Adolescents

    DEFF Research Database (Denmark)

    Vesikari, Timo; Østergaard, Lars Jørgen; Diez-Domingo, Javier;

    2015-01-01

    BACKGROUND: Neisseria meningitidis serogroup B (MnB) is a leading cause of invasive meningococcal disease in adolescents and young adults. A recombinant factor H binding protein (fHBP) vaccine (Trumenba(®); bivalent rLP2086) was recently approved in the United States in individuals aged 10-25 yea...

  18. Synthesis and characterization of silver nanoparticles from Alpinia calcarata by Green approach and its applications in bactericidal and nonlinear optics

    Science.gov (United States)

    Pugazhendhi, S.; Kirubha, E.; Palanisamy, P. K.; Gopalakrishnan, R.

    2015-12-01

    Development of green route for the synthesis of nanoparticles with plant extracts plays a very important role in nanotechnology without any toxicity chemicals. Herein we report a new approach to synthesize silver nanoparticles (AgNPs) using aqueous extract of Alpinia calcarata root as a reducing as well as stabilizing agent. The crystal structure and purity of the synthesized AgNPs were studied using Powder X-ray Diffraction analysis. The Surface Plasmon Resonance bands of synthesized silver nanoparticles have been obtained and monitored using UV-Visible spectrum. The morphologies of the AgNPs were analyzed using High resolution transmission electron microscopy (HRTEM). The elements present in the A. calcarata extract were determined by the inductively coupled plasma-optical emission Spectrometry (ICP-OES) and Fourier transform infrared spectroscopy (FTIR). Silver nanoparticles from A. calcarata possess very good antimicrobial activity which was confirmed by resazurin dye reduction assay method and thus it is a potential source of antimicrobial agent. The synthesized Ag nanoparticles exhibit good optical nonlinearity and the nonlinear optical studies have been carried out by Z-scan technique.

  19. Bactericidal effects of silver plus titanium dioxide-coated endotracheal tubes on Pseudomonas aeruginosa and Staphylococcus aureus

    OpenAIRE

    Tarquinio, Keiko

    2010-01-01

    Keiko M Tarquinio1, Nikhil K Kothurkar2, Dharendra Y Goswami3, Ronald C Sanders Jr4, Arno L Zaritsky5, Ann Marie LeVine61Division of Pediatric Critical Care Medicine, Department of Pediatrics, Rhode Island Hospital, The Warren Alpert Medical School, Brown University, Providence, RI USA; 2Department of Chemical Engineering and Materials Science, Amrita School of Engineering, Ettimadai, Coimbatore, India; 3Clean Energy Research Center, University of South Florida, Tampa, FL, USA; 4Section of Pe...

  20. Short-term bactericidal efficacy of lauric arginate against Listeria monocytogenes present on the surface of frankfurters.

    Science.gov (United States)

    Taormina, P J; Dorsa, W J

    2009-06-01

    The antimicrobial lauric arginate (LAE) alone or in combination with an antimicrobial liquid smoke extract was studied as a postlethality treatment against Listeria monocytogenes on vacuum-packaged frankfurters. Treatment with 2 ml of 5,000 ppm of LAE reduced L. monocytogenes from 7.13 to 5.82 log CFU per package on day 0, and treatment with 3 ml reduced populations from 7.22 to 5.79 log CFU per package on day 0. Treatment with LAE and smoke flavor did not result in significantly different populations of L. monocytogenes (P or = 1.68 log CFU per package, and many of the treatments caused a > 2-log reduction within 48 h. In this study, the shortterm efficacy of LAE against L. monocytogenes on vacuum-packaged frankfurters was demonstrated, providing support for use of this postlethality treatment on frankfurters and sausages for control of this pathogen. PMID:19610332

  1. Bactericidal effects of silver plus titanium dioxide-coated endotracheal tubes on Pseudomonas aeruginosa and Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Keiko M Tarquinio

    2010-03-01

    Full Text Available Keiko M Tarquinio1, Nikhil K Kothurkar2, Dharendra Y Goswami3, Ronald C Sanders Jr4, Arno L Zaritsky5, Ann Marie LeVine61Division of Pediatric Critical Care Medicine, Department of Pediatrics, Rhode Island Hospital, The Warren Alpert Medical School, Brown University, Providence, RI USA; 2Department of Chemical Engineering and Materials Science, Amrita School of Engineering, Ettimadai, Coimbatore, India; 3Clean Energy Research Center, University of South Florida, Tampa, FL, USA; 4Section of Pediatric Critical Care, Department of Pediatrics, College of Medicine, University of Arkansas for Medical Sciences, Arkansas Children’s Hospital, Little Rock, AR, USA; 5Executive Medical Director, Children’s Hospital of The King’s Daughters, Norfolk, VA, USA; 6Pediatric Critical Care Medicine, University of Michigan Medical School, C.S. Mott Children’s Hospital, Ann Arbor, MI, USAPurpose: Ventilator-associated pneumonia (VAP is a nosocomial infection resulting in significant morbidity and mortality. Pseudomonas aeruginosa (P. aeruginosa and Staphylococcus aureus (S. aureus are pathogens associated with VAP. Silver (Ag coating of endotracheal tubes (ETTs reduces bacterial colonization, however titanium dioxide (TiO2 coating has not been studied.Methods: Five types of ETT coatings were applied over silica layer: Ag, solgel TiO2, solgel TiO2 with Ag, Degussa P25 TiO2 (Degussa TiO2, and Degussa TiO2 with Ag. After ETTs were incubated with P. aeruginosa or S. aureus; colonization was determined quantitatively.Results: Pseudomonas aeruginosa and S. aureus grew for 5 days on standard ETTs. Compared to standard ETTs, P. aeruginosa growth was significantly inhibited by solgel TiO2 with Ag at 24 hours, and by Degussa TiO2 with Ag at 24 and 48 hours after inoculation. No significant difference in S. aureus growth was observed between the control and any of the five coatings for 5 days.Conclusion: In vitro, solgel TiO2 with Ag and Degussa TiO2 with Ag both attenuated P. aeruginosa growth, but demonstrated no effect on S. aureus colonization. Further studies using alternative coating and incorporating UV light exposure are needed to identify their potential utility in reducing VAP.Keywords: ventilator-associated pneumonia, Degussa titanium dioxide, solgel titanium dioxide, quantitative culture

  2. Efecto bactericida del láser de diodo en periodoncia Bactericidal effects of diode laser in periodontology

    OpenAIRE

    G Caccianiga; E. Urso; R Monguzzi; K Gallo; Rey, G.

    2008-01-01

    El láser en odontología, gracias a su capacidad antibacteriana, hemostática y de menor sintomatología operatoria, encuentra un amplio campo de aplicación en el ámbito de la terapia periodontal. En este estudio ha sido probada la eficacia de un protocolo que prevé el utilizo asociado de irradiación láser y de agua oxigenada con el fin de reducir a carga bacteriana de cepas comúnmente presentes en las bolsas periodontales activas y resistentes a la acción bactericida de solamente la irradiación...

  3. Research and Application of TCMTB on Paper Bactericide%TCMTB造纸杀菌剂的研究与应用

    Institute of Scientific and Technical Information of China (English)

    赵天翼; 黄奇然; 李少清; 杨伟和

    2011-01-01

    根据工业杀菌剂不同活性成分的物化特性进行复配研究,研制开发了具有高效、广谱的复合型TCMTB造纸杀菌剂,解决目前市场上大多杀菌剂活性成分单一、用量大、易产生抗药性等问题,从而有效地控制造纸过程的微生物问题,抑制腐浆的形成,保证纸机的正常生产,延长停机清洗周期.

  4. Bactericidal effect of selected antidiarrhoeal medicinal plants on intracellular heat-stable enterotoxin-producing Escherichia coli

    Directory of Open Access Journals (Sweden)

    Tannaz J. Birdi

    2014-01-01

    Full Text Available Diarrhoeal diseases due to enterotoxigenic Escherichia coli continue to be a cause of global concern. Medicinal plants have been gaining popularity as promising antidiarrhoeal agents. In the present study, four antidiarrhoeal plants, viz. Aegle marmelos, Cyperus rotundus, Psidium guajava and Zingiber officinale were screened against a heat-stable toxin-producing enterotoxigenic E. coli strain. Decoctions of these plants were studied for their effect on intracellular killing of the bacterial strain using murine monocytic cell line, J774. [ 3 H] thymidine release assay was used to evaluate the apoptotic/necrotic effect. All plants at concentrations <1% enhanced intracellular killing of the bacteria by J774 cells. However, at higher concentrations, the decoctions induced apoptosis in J774 cells. The study demonstrates that these plants could control diarrhoea caused by heat-stable toxin-producing enterotoxigenic E. coli through their immunomodulatory effect.

  5. Bactericidal activity of the food color additive Phloxine B against Staphylococcus aureus and other food borne microbial pathogens

    Science.gov (United States)

    The spread of antibiotic resistance among Staphylococcus aureus strains requires the development of new anti S. aureus agents. The objective of this study was evaluating the antimicrobial activity of the food color additive Phloxine B against S. aureus and other food microbial pathogens. Our result ...

  6. Role of UV radiation, solution conductivity and pulse repetition frequency in the bactericidal effects during pulse corona discharge in water

    Czech Academy of Sciences Publication Activity Database

    Špetlíková, E.; Janda, V.; Lukeš, Petr; Člupek, Martin

    Prague: MATFYZPRESS, 2010 - (Šafránková, J.; Pavlů, J.), s. 96-100 ISBN 978-80-7378-140-8. [Annual Student Conference Week of Doctoral Students 2010/19th./. Prague (CZ), 01.06.2010-04.06.2010] R&D Projects: GA ČR(CZ) GD104/09/H080; GA AV ČR IAAX00430802 Institutional research plan: CEZ:AV0Z20430508 Keywords : corona discharge * ultraviolet radiation * E.coli * E. faecalis Subject RIV: BL - Plasma and Gas Discharge Physics http://www.mff.cuni.cz/veda/konference/wds/contents/wds10.htm

  7. Physical and bactericidal properties of TiO.sub.2./sub. layers prepared by PLD andcombination PLD and RF discharge

    Czech Academy of Sciences Publication Activity Database

    Remsa, Jan; Jelínek, Miroslav; Mikšovský, J.; Kocourek, Tomáš; Weiserová, Marie

    Strasbourg: EMRS, 2010. 16 RPII29. [E- MRS 2010 Spring: Laser processing and diagnostics for micro and nano applications. 07.06.2010-11.06.2010, Strasbourg] Institutional research plan: CEZ:AV0Z10100522; CEZ:AV0Z50200510 Keywords : PLD * thin film * TiO 2 * RF * Escherichia coli Subject RIV: BH - Optics, Masers, Lasers

  8. Investigation of Diospyros Kaki L.f husk extracts as corrosion inhibitors and bactericide in oil field

    OpenAIRE

    Zhang, Jie; Song, Yingpan; Su, Huijun; ZHANG Li; Chen, Gang; Zhao, Jingrui

    2013-01-01

    Background Hydrochloric acid is used in oil-well acidizing commonly for improving the crude oil production of the low-permeable reservoirs, while it is a great challenge for the metal instruments involved in the acidification. Developing natural products as oilfield chemicals is a straight way to find less expensive, green and eco-friendly materials. The great plant resources in Qin-ling and Ba-shan Mountain Area of Shannxi Province enable the investigating of new green oil field chemicals. D...

  9. Tin Oxide-Silver Composite Nanomaterial Coating for UV Protection and Its Bactericidal Effect on Escherichia coli (E. coli

    Directory of Open Access Journals (Sweden)

    Gil Nonato C. Santos

    2014-05-01

    Full Text Available SnO2-Ag composite nanomaterials of mass ratio 1:4, 2:3, 3:2 and 4:1 were fabricated and tested for toxicity to E. coli using the pour-plate technique. The said nanomaterials were mixed with laminating fluid and then coated on glass slides. The intensity of UVA transmitted through the coated glass slides was measured. Results revealed that the 1:4 ratios of SnO2-Ag composite nanomaterials have the optimum toxicity to E. coli. Furthermore, the glass slides coated with SnO2 nanomaterial showed the lowest intensity of transmitted UVA.

  10. Relating the Surface Properties of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) to Their Bactericidal Effect towards a Biofilm of Streptococcus mutans

    Science.gov (United States)

    Javanbakht, Taraneh; Laurent, Sophie; Stanicki, Dimitri; Wilkinson, Kevin J.

    2016-01-01

    This study was designed to determine the effects of superparamagnetic iron oxide nanoparticles (SPIONs) on the biological activity of a bacterial biofilm (Streptococcus mutans). Our hypothesis was that the diffusion of the SPIONs into biofilms would depend on their surface properties, which in turn would largely be determined by their surface functionality. Bare, positively charged and negatively charged SPIONs, with hydrodynamic diameters of 14.6 ± 1.4 nm, 20.4 ± 1.3 nm and 21.2 ± 1.6 nm were evaluated. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and electrophoretic mobility (EPM) measurements were used to confirm that carboxylic functional groups predominated on the negatively charged SPIONS, whereas amine functional groups predominated on the positively charged particles. Transmission electron microscopy (TEM) showed the morphology and sizes of SPIONs. Scanning electron microscopy (SEM) and EPM measurements indicated that the surfaces of the SPIONs were covered with biomolecules following their incubation with the biofilm. Bare SPIONs killed bacteria less than the positively charged SPIONs at the highest exposure concentrations, but the toxicity of the bare and positively charged SPIONs was the same for lower SPION concentrations. The positively charged SPIONs were more effective in killing bacteria than the negatively charged ones. Nonetheless, electrophoretic mobilities of all three SPIONs (negative, bare and positively charged) became more negative following incubation with the (negatively-charged) biofilm. Therefore, while the surface charge of SPIONS was important in determining their biological activity, the initial surface charge was not constant in the presence of the biofilm, leading eventually to SPIONS with fairly similar surface charges in situ. The study nonetheless suggests that the surface characteristics of the SPIONS is an important parameter controlling the efficiency of antimicrobial agents. The analysis of the CFU/mL values shows that the SPIONs have the same toxicity on bacteria in solution in comparison with that on the biofilm. PMID:27115356

  11. The bactericidal effect of 470 nm light and hyperbaric oxygen on methicillin-resistant Staphylococcus aureus (MRSA)

    OpenAIRE

    Bumah, Violet Vakunseh; Whelan, Harry Thomas; Masson-Meyers, Daniela Santos; Quirk, Brendan; Buchmann, Ellen; Enwemeka, Chukuka Samuel

    2015-01-01

    It has been shown that, in vitro, hyperbaric oxygen (HBO) suppresses 28% bacterial growth, while 470 nm blue light alone suppresses up to 92% methicillin resistant Staphylococcus aureus (MRSA) in one application in vitro. Therefore, we determined if combined 470 nm light (55 J/cm2) and HBO will yield 100% bacterial suppression in experimental simulation of mild, moderate or severe MRSA infection. We cultured MRSA at 3×106, 5×106, 7×106, 8×106 or 12×106 CFU/ml and treated each concentration in...

  12. Bactericidal, structural and morphological properties of ZnO2 nanoparticles synthesized under UV or ultrasound irradiation

    Science.gov (United States)

    Colonia, R.; Solís, J. L.; Gómez, M.

    2014-03-01

    Nanoparticles of ZnO2 were synthesized by a sol-gel method using Zn(CH3COO)2 and H2O2 in an aqueous solution exposed to either ultraviolet (UV) or ultrasound irradiation. X-ray diffraction and scanning electron microscopy showed that the nanostructures consisted of spherical blackberry-like clusters. Nanoparticles fabricated by using UV irradiation had smaller sizes and narrower size distributions than nanoparticles prepared by using ultrasound. Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were used as test microorganisms, and the antibacterial activity of the ZnO2 nanoparticles was studied by use of the well diffusion agar bacteriological test. ZnO2 nanoparticles synthetized using UV had the best antibacterial properties. The inhibition zone was largest for B. subtilis but was present also for S. aureus and E. coli.

  13. Bactericidal, structural and morphological properties of ZnO2 nanoparticles synthesized under UV or ultrasound irradiation

    International Nuclear Information System (INIS)

    Nanoparticles of ZnO2 were synthesized by a sol–gel method using Zn(CH3COO)2 and H2O2 in an aqueous solution exposed to either ultraviolet (UV) or ultrasound irradiation. X-ray diffraction and scanning electron microscopy showed that the nanostructures consisted of spherical blackberry-like clusters. Nanoparticles fabricated by using UV irradiation had smaller sizes and narrower size distributions than nanoparticles prepared by using ultrasound. Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were used as test microorganisms, and the antibacterial activity of the ZnO2 nanoparticles was studied by use of the well diffusion agar bacteriological test. ZnO2 nanoparticles synthetized using UV had the best antibacterial properties. The inhibition zone was largest for B. subtilis but was present also for S. aureus and E. coli. (paper)

  14. Extracellular synthesis of silver nanoparticles by novel Pseudomonas veronii AS41G inhabiting Annona squamosa L. and their bactericidal activity

    Science.gov (United States)

    Baker, Syed; Mohan Kumar, K.; Santosh, P.; Rakshith, D.; Satish, S.

    2015-02-01

    In present investigation extracellular synthesis of silver nanoparticles were synthesized using cell free supernatant of Pseudomonas veronii AS41G isolated from Annona squamosa L. The bacterium significantly reduced silver nitrate to generate silver nanoparticles which was characterized with hyphenated techniques. Synthesis of silver nanoparticles preliminary confirmed by UV-Visible spectrophotometry with the intense peak at 410 nm, Further FTIR analysis revealed the possible role of biomolecules in the supernatant responsible for mediating the nanoparticles formation. The XRD spectra exhibited the characteristic Bragg peaks of 1 0 0, 1 1 1, 2 0 0, and 2 2 0 facets of the face centred cubic symmetry of nanoparticles suggesting that these nanoparticles were crystalline in nature. TEM microgram showed polydispersity of nanoparticles with size ranging from 5 to 50 nm. Synthesized silver nanoparticles showed antibacterial activity against human and environmental pathogens including MRSA. The study enlightens the role of biosynthesized silver nanoparticles as an emerging alternative for drug resistant microorganisms. The obtained results are promising enough to pave the environmentally benign nanoparticle synthesis processes without use of any toxic chemicals and also envision the emerging role of endophytes towards synthesis of nanoparticles. With scanty reports available on P.veronii species, a new role has been reported in this study which will be very valuable for future researchers working on it.

  15. Monoclonal antibodies against the iron regulated outer membrane Proteins of Acinetobacter baumannii are bactericidal

    OpenAIRE

    Goel Vikas; Kapil Arti

    2001-01-01

    Abstract Background Iron is an important nutrient required by all forms of life.In the case of human hosts,the free iron availability is 10-18M,which is far less than what is needed for the survival of the invading bacterial pathogen.To survive in such conditions, bacteria express new proteins in their outer membrane and also secrete iron chelators called siderophores. Results/ Discussion Acinetobacter baumannii ATCC 19606, a nosocomial pathogen which grows under iron restricted conditions, e...

  16. Synthesis of Copper Oxide (CuO) Nanoparticles and Surveying Its Bactericidal Properties against Aeromonas Hydrophila Bacteria

    OpenAIRE

    SF Shaffiey; Ahmadi, M; SR Shaffiey; M Shapoori; H Varshoie; F Azari

    2015-01-01

    Background & Objective: CuO is one of the most important transition metal oxides due to its exclusive properties. It is used in various technological applications such as superconductors and gas sensors. Recently, it has been used as an antimicrobial agent against various bacterial species. In this study, we synthesized CuO nanoparticles and evaluated their antibacterial property.  Materials & Methods: Single crystalline nanoparticles of copper oxide having almost unif...

  17. Simultaneous pharmacodynamic analysis of the lag and bactericidal phases exhibited by beta-lactams against Escherichia coli.

    OpenAIRE

    Li, R C

    1996-01-01

    Antibiotic-bacterium interactions are complex in nature. In many cases, bacterial killing does not commence immediately after the addition of an antibiotic, and a lag period is observed. Antibiotic permeation and/or the intermediate steps that exist between antibiotic-receptor binding and expression of cell death are two major possible causes for such lag period. This study was primarily designed to determine the relationship, if any, between antibiotic concentrations and the lag periods by a...

  18. Fabrication of silver nanoparticle-doped hydroxyapatite coatings with oriented block arrays for enhancing bactericidal effect and osteoinductivity.

    Science.gov (United States)

    Tian, Bo; Chen, Wei; Yu, Degang; Lei, Yong; Ke, Qinfei; Guo, Yaping; Zhu, Zhenan

    2016-08-01

    Implant-associated infection is a common postoperative complication and remains a serious problem in orthopedic surgery. This work describes the synthesis of silver nanoparticle-doped hydroxyapatite coatings with oriented block arrays (AgNP-BHAC). The resulting nanostructure was investigated using scanning electron microscopy, energy-dispersive spectrometry, transmission electron microscopy, X-ray powder diffraction, and Fourier transform infrared spectroscopy. AgNP-BHAC exhibited excellent antimicrobial activity toward gram-negative Escherichia coli and gram-positive Staphylococcus aureus owing to the antibacterial effects of the silver nanoparticles. Human bone marrow stromal cells (hBMSC) culture revealed that the AgNP-BHAC exhibited better biocompatibility, and permitted improved cell proliferation, attachment, and osteoinductivity than uncoated Ti-6Al-4V titanium alloy, the favored material for biomedical applications. In summary, this study presents a convenient and effective method for the incorporation of silver into HA coatings with block morphology. This method can be utilized to modify a variety of metallic implant surfaces to improve their antimicrobial effects and reduce potential long-term cytotoxicity. PMID:27107263

  19. Formation of ROS and RNS in Water Electro-Sprayed through Transient Spark Discharge in Air and their Bactericidal Effects

    Czech Academy of Sciences Publication Activity Database

    Machala, Z.; Tarabová, B.; Hensel, K.; Doležalová, Eva; Šikurová, L.; Lukeš, Petr

    2013-01-01

    Roč. 10, č. 7 (2013), s. 649-659. ISSN 1612-8850 R&D Projects: GA AV ČR IAAX00430802; GA ČR(CZ) GD104/09/H080; GA MŠk(CZ) MEB0810116 Institutional support: RVO:61389021 Keywords : Plasma electrospray * water * bacteria * hydrogen peroxide * peroxynitrite * cold plasma * water electro-spray Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.964, year: 2013 http://dx.doi.org/10.1002/ppap.201200113

  20. Formation of hydroxyl radicals contributes to the bactericidal activity of ciprofloxacin against Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Jensen, Peter Ø.; Briales, Alejandra; Brochmann, Rikke Prejh;

    2014-01-01

    induction of cytotoxic hydroxyl radicals (OH˙) during antibiotic treatment of planktonically grown cells may contribute to action of the commonly used antibiotic ciprofloxacin on P. aeruginosa biofilms. For this purpose, WT PAO1, a catalase deficient ΔkatA and a ciprofloxacin resistant mutant of PAO1 (gyr......A), were grown as biofilms in microtiter plates and treated with ciprofloxacin. Formation of OH˙ and total amount of reactive oxygen species (ROS) was measured and viability was estimated. Formation of OH˙ and total ROS in PAO1 biofilms treated with ciprofloxacin was shown but higher levels were measured...... in ΔkatA biofilms, and no ROS production was seen in the gyrA biofilms. Treatment with ciprofloxacin decreased the viability of PAO1 and ΔkatA biofilms but not of gyrA biofilms. Addition of thiourea, a OH˙ scavenger, decreased the OH˙ levels and killing of PAO1 biofilm. Our study shows that OH˙ is...

  1. Bactericidal activity of ciprofloxacin against amikacin- and cefotaxime-resistant gram-negative bacilli and methicillin-resistant staphylococci.

    OpenAIRE

    Simberkoff, M S; Rahal, J J

    1986-01-01

    The MICs and MBCs of ciprofloxacin were determined for clinical isolates of antibiotic-resistant aerobic bacteria. Decreased susceptibility to ciprofloxacin of cefotaxime- and amikacin-resistant Serratia marcescens and amikacin-resistant Pseudomonas aeruginosa strains were noted. The data suggest that ciprofloxacin susceptibility should be carefully monitored in treating patients with hospital-acquired bacterial infections.

  2. Bactericidal Activity of Aqueous Acrylic Paint Dispersion for Wooden Substrates Based on TiO2 Nanoparticles Activated by Fluorescent Light

    Directory of Open Access Journals (Sweden)

    Diana Di Gioia

    2013-08-01

    Full Text Available The photocatalytic effect of TiO2 has great potential for the disinfection of surfaces. Most studies reported in the literature use UV activation of TiO2, while visible light has been used only in a few applications. In these studies, high concentrations of TiO2, which can compromise surface properties, have been used. In this work, we have developed an acrylic-water paint dispersion containing low TiO2 content (2 vol % for the inactivation of microorganisms involved in hospital-acquired infections. The nanoparticles and the coating have been characterized using spectroscopic techniques and transmission electron microscopy, showing their homogenous dispersion in the acrylic urethane coating. A common fluorescent light source was used to activate the photocatalytic activity of TiO2. The paint dispersion showed antimicrobial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The coating containing the TiO2 nanoparticles maintained good UV stability, strong adhesion to the substrate and high hardness. Therefore, the approach used is feasible for paint formulation aimed at disinfection of healthcare surfaces.

  3. Inhalable Particles for "Pincer Therapeutics" Targeting Nitazoxanide as Bactericidal and Host-Directed Agent to Macrophages in a Mouse Model of Tuberculosis.

    Science.gov (United States)

    Gupta, Anuradha; Meena, Jairam; Sharma, Deepak; Gupta, Pushpa; Gupta, Umesh Dutta; Kumar, Sadan; Sharma, Sharad; Panda, Amulya K; Misra, Amit

    2016-09-01

    Nitazoxanide (NTZ) has moderate mycobactericidal activity and is also an inducer of autophagy in mammalian cells. High-payload (40-50% w/w) inhalable particles containing NTZ alone or in combination with antituberculosis (TB) agents isoniazid (INH) and rifabutin (RFB) were prepared with high incorporation efficiency of 92%. In vitro drug release was corrected for drug degradation during the course of study and revealed first-order controlled release. Particles were efficiently taken up in vitro by macrophages and maintained intracellular drug concentrations at one order of magnitude higher than NTZ in solution for 6 h. Dose-dependent killing of Mtb and restoration of lung and spleen architecture were observed in experimentally infected mice treated with inhalations containing NTZ. Adjunct NTZ with INH and RFB cleared culturable bacteria from the lung and spleen and markedly healed tissue architecture. NTZ can be used in combination with INH-RFB to kill the pathogen and heal the host. PMID:27463245

  4. Bactericidal action of carvacrol towards the food pathogen Bacillus cereus : A case study of a novel approach to mild food preservation

    NARCIS (Netherlands)

    Ultee, A.

    2000-01-01

    A new trend in food preservation is the use of mild preservation systems, instead of more severe techniques such as heating, freezing or addition of chemical preservatives. Carvacrol, a phenolic compound present in the essential oil fraction of oreganum and thyme, is known for its antimicrobial acti

  5. 皮革防霉剂的现状与发展%The Present Situation and Development of the Leather Bactericide

    Institute of Scientific and Technical Information of China (English)

    李志坚; 杨伟和; 邱芙坚

    2002-01-01

    杀菌防霉是皮革工业的一个必要环节。由于法规和环保的要求,选择一种高效低毒的防霉剂是非常重要的,寻求具有协同效果的杀菌剂配方,是目前国际上新型工业杀菌剂研究的主流方向。TCMTB具有可靠的广谱杀菌活性,毒性低,性价比高。TCMTB其无比的优越性取得了世界各国的认同,并在皮革市场上获得了成功的应用。

  6. Destabilization of α-Helical Structure in Solution Improves Bactericidal Activity of Antimicrobial Peptides: Opposite Effects on Bacterial and Viral Targets

    OpenAIRE

    Ulaeto, David O.; Morris, Christopher J.; Fox, Marc A.; Gumbleton, Mark; Beck, Konrad

    2016-01-01

    We have previously examined the mechanism of antimicrobial peptides on the outer membrane of vaccinia virus. We show here that the formulation of peptides LL37 and magainin-2B amide in polysorbate 20 (Tween 20) results in greater reductions in virus titer than formulation without detergent, and the effect is replicated by substitution of polysorbate 20 with high-ionic-strength buffer. In contrast, formulation with polysorbate 20 or high-ionic-strength buffer has the opposite effect on bacteri...

  7. Bordetella pertussis Adenylate Cyclase Toxin Blocks Induction of Bactericidal Nitric Oxide in Macrophages through cAMP-Dependent Activation of the SHP-1 Phosphatase

    Czech Academy of Sciences Publication Activity Database

    Černý, Ondřej; Kamanová, Jana; Mašín, Jiří; Bíbová, Ilona; Škopová, Karolína; Šebo, Peter

    2015-01-01

    Roč. 194, č. 10 (2015), s. 4901-4913. ISSN 0022-1767 R&D Projects: GA ČR GAP302/12/0460; GA ČR GA13-14547S Institutional support: RVO:61388971 Keywords : CYCLIC-AMP * MURINE MACROPHAGES * IFN-GAMMA Subject RIV: EE - Microbiology, Virology Impact factor: 4.922, year: 2014

  8. A Thermostable Salmonella Phage Endolysin, Lys68, with Broad Bactericidal Properties against Gram-Negative Pathogens in Presence of Weak Acids

    DEFF Research Database (Denmark)

    Oliveira, Hugo; Thiagarajan, Viruthachalam; Walmagh, Maarten;

    2014-01-01

    circular dichroism analysis demonstrated the ability to refold into its original conformation upon thermal denaturation. It was shown that Lys68 is able to lyse a wide panel of Gram-negative bacteria (13 different species) in combination with the outer membrane permeabilizers EDTA, citric and malic acid....... While the EDTA/Lys68 combination only inactivated Pseudomonas strains, the use of citric or malic acid broadened Lys68 antibacterial effect to other Gram-negative pathogens (lytic activity against 9 and 11 species, respectively). Particularly against Salmonella Typhimurium LT2, the combinatory effect of...... malic or citric acid with Lys68 led to approximately 3 to 5 log reductions in bacterial load/CFUs after 2 hours, respectively, and was also able to reduce stationary-phase cells and bacterial biofilms by approximately 1 log. The broad killing capacity of malic/citric acid-Lys68 is explained by the...

  9. A thermostable Salmonella phage endolysin, Lys68, with broad bactericidal properties against gram-negative pathogens in presence of weak acids.

    Directory of Open Access Journals (Sweden)

    Hugo Oliveira

    Full Text Available Resistance rates are increasing among several problematic Gram-negative pathogens, a fact that has encouraged the development of new antimicrobial agents. This paper characterizes a Salmonella phage endolysin (Lys68 and demonstrates its potential antimicrobial effectiveness when combined with organic acids towards Gram-negative pathogens. Biochemical characterization reveals that Lys68 is more active at pH 7.0, maintaining 76.7% of its activity when stored at 4°C for two months. Thermostability tests showed that Lys68 is only completely inactivated upon exposure to 100°C for 30 min, and circular dichroism analysis demonstrated the ability to refold into its original conformation upon thermal denaturation. It was shown that Lys68 is able to lyse a wide panel of Gram-negative bacteria (13 different species in combination with the outer membrane permeabilizers EDTA, citric and malic acid. While the EDTA/Lys68 combination only inactivated Pseudomonas strains, the use of citric or malic acid broadened Lys68 antibacterial effect to other Gram-negative pathogens (lytic activity against 9 and 11 species, respectively. Particularly against Salmonella Typhimurium LT2, the combinatory effect of malic or citric acid with Lys68 led to approximately 3 to 5 log reductions in bacterial load/CFUs after 2 hours, respectively, and was also able to reduce stationary-phase cells and bacterial biofilms by approximately 1 log. The broad killing capacity of malic/citric acid-Lys68 is explained by the destabilization and major disruptions of the cell outer membrane integrity due to the acidity caused by the organic acids and a relatively high muralytic activity of Lys68 at low pH. Lys68 demonstrates good (thermostability properties that combined with different outer membrane permeabilizers, could become useful to combat Gram-negative pathogens in agricultural, food and medical industry.

  10. Isolation, structural and functional characterization of a new Lys49 phospholipase A2 homologue from Bothrops neuwiedi urutu with bactericidal potential.

    Science.gov (United States)

    Corrêa, Edailson A; Kayano, Anderson M; Diniz-Sousa, Rafaela; Setúbal, Sulamita S; Zanchi, Fernando B; Zuliani, Juliana P; Matos, Najla B; Almeida, José R; Resende, Letícia M; Marangoni, Sérgio; da Silva, Saulo L; Soares, Andreimar M; Calderon, Leonardo A

    2016-06-01

    Snake venom is a complex mixture of active compounds consisting of 80-90% proteins and peptides that exhibit a variety of biological actions that are not completely clarified or identified. Of these, phospholipase A2 is one of the molecules that has shown great biotechnological potential. The objectives of this study were to isolate, biochemically and biologically characterize a Lys49 phospholipase A2 homologue from the venom of Bothrops neuwiedi urutu. The protein was purified after two chromatographic steps, anion exchange and reverse phase. The purity and relative molecular mass were assessed by SDS-PAGE, observing a molecular weight typical of PLA2s, subsequently confirmed by mass spectrometry obtaining a mass of 13,733 Da. As for phospholipase activity, the PLA2 proved to be enzymatically inactive. The analyses by Edman degradation and sequencing of the peptide fragments allowed for the identification of 108 amino acid residues; this sequence showed high identity with other phospholipases A2 from Bothrops snake venoms, and identified this molecule as a novel PLA2 isoform from B. neuwiedi urutu venom, called BnuTX-I. In murine models, both BnuTX-I as well as the venom induced edema and myotoxic responses. The cytotoxic effect of BnuTX-I in murine macrophages was observed at concentrations above 12 μg/mL. BnuTX-I also presented antimicrobial activity against gram-positive and negative bacterial strains, having the greatest inhibitory effect on Pseudomonas aeruginosa. The results allowed for the identification of a new myotoxin isoform with PLA2 structure with promising biotechnological applications. PMID:26927324

  11. Bactericidal effect of visible light in the presence of erythrosine on Porphyromonas gingivalis and Fusobacterium nucleatum compared with diode laser, an in vitro study

    OpenAIRE

    Habiboallah, Ghanbari; Mahdi, Zakeri; Mahbobeh, Naderi Nasab; Mina, Zareian Jahromi; Sina, Faghihi; Majid, Zakeri

    2014-01-01

    Objectives: Recently, photodynamic therapy (PDT) has been introduced as a new modality in oral bacterial decontamination. Besides, the ability of laser irradiation in the presence of photosensitizing agent to lethal effect on oral bacteria is well documented. Current research aims to evaluate the effect of photodynamic killing of visible blue light in the presence of plaque disclosing agent erythrosine as photosensitizer on Porphyromonas gingivalis associated with periodontal bone loss and Fu...

  12. Inhibition of C5a-induced inflammation with preserved C5b-9-mediated bactericidal activity in a human whole blood model of meningococcal sepsis.

    NARCIS (Netherlands)

    Sprong, T.; Brandtzaeg, P.; Fung, M.; Pharo, A.M.; Hoiby, E.A.; Michaelsen, T.E.; Aase, A.; Meer, J.W.M. van der; Deuren, M. van; Mollnes, T.E.

    2003-01-01

    The complement system plays an important role in the initial defense against Neisseria meningitidis. In contrast, uncontrolled activation in meningococcal sepsis contributes to the development of tissue damage and shock. In a novel human whole blood model of meningococcal sepsis, we studied the effe

  13. Stem Bark Extract and Fraction of Persea americana (Mill.) Exhibits Bactericidal Activities against Strains of Bacillus cereus Associated with Food Poisoning

    OpenAIRE

    Akinpelu, David A.; Aiyegoro, Olayinka A.; Akinpelu, Oluseun F.; Okoh, Anthony I.

    2014-01-01

    The study investigates the in vitro antibacterial potentials of stem bark extracts of Persea americana on strains of Bacillus cereus implicated in food poisoning. The crude stem bark extracts and butanolic fraction at a concentration of 25 mg/mL and 10 mg/mL, respectively, exhibited antibacterial activities against test isolates. The zones of inhibition exhibited by the crude extract and the fraction ranged between 10 mm and 26 mm, while the minimum inhibitory concentration values ranged betw...

  14. Concentrations of lipopolysaccharide-binding protein, bactericidal/permeability-increasing protein, soluble CD14 and plasma lipids in relation to endotoxaemia in patients with alcoholic liver disease

    DEFF Research Database (Denmark)

    Schäfer, C.; Parlesak, Alexandr; Schütt, C.;

    2002-01-01

    There is increasing evidence that gut leakage in persons with chronic alcohol misuse leads to endotoxaemia, which might contribute to the development of alcoholic hepatitis or cirrhosis. In addition, it was recently shown that the endotoxin-binding capacity of whole blood is reduced in these pati...

  15. In掺杂纳米ZnO杀菌性能的研究%Studies on the bactericidal performance of indium doped nano-zinc oxide

    Institute of Scientific and Technical Information of China (English)

    赵艳凝; 滕洪辉; 常立民; 文福姬

    2008-01-01

    分别在自然光、紫外光的光照下,研究了纳米ZnO与In掺杂纳米ZnO对大肠杆菌的杀菌性能,并对其杀菌机理进行初步探讨.通过对比得出结论:在相同浓度与温度条件下,采用紫外光照射的杀菌效果均优于自然光下的杀菌效果;采用In掺杂纳米ZnO对大肠杆菌的杀菌率高于纳米ZnO的杀菌率.其机理足In掺杂量很低(0.5%)的情况下,导致了整个体系能带的窄化,从而提高了纳米ZnO的杀菌降解性能.

  16. The efficiency of the bactericidal action of serum raised by complement and lysozyme against bacteria which avoid the immunological response of higher organisms

    Directory of Open Access Journals (Sweden)

    Bożena Futoma-Kołoch

    2009-10-01

    Full Text Available This paper presents some processes of the antibacterial effect of serum, which mainly results from the activities of complement (C and lysozyme (muramidase, LZ. The C system consists of a group of serum proteins and tissue fluids which are activated in a particular order. Complement, operating together with lysozyme, constitutes the main protection from microorganisms entering the body. Pathogenic microorganisms are able to avoid natural protective mechanisms by, among others, molecular mimicry, binding complement control proteins, or secreting proteolytic enzymes. The effectiveness of the cytolytic action of C proteins and LZ also depends on the surface structures of the microorganisms. Imbalance between the activation and deactivation of inflammatory reactions in the presence of pathogens can lead to various pathological states, such as autoimmunological diseases.

  17. Aqueous-phase chemistry and bactericidal effects from an air discharge plasma in contact with water: Evidence for the formation of peroxynitrite through a pseudo-second-order post-discharge reaction of H2O2 and HNO2

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Doležalová, Eva; Sisrová, Irena; Člupek, Martin

    2014-01-01

    Roč. 23, č. 1 (2014), 015019-015019. ISSN 0963-0252 Grant ostatní: Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100431203 Institutional support: RVO:61389021 Keywords : air discharge plasma * plasma–liquid interactions * peroxynitrite * hydrogen peroxide * phenol * bacteria Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.591, year: 2014 http://iopscience.iop.org/0963-0252/23/1/015019/pdf/0963-0252_23_1_015019.pdf

  18. Evaluación de la Actividad Bactericida de Bacterias Ácido Lácticas Aisladas en Calostro de Cerdas Frente a Salmonella typhimurium / Bactericidal Evaluation of Lactic Acid Bacteria Isolated in Sow Colostrum Against Salmonella tiphymurium

    OpenAIRE

    Juliana María Vélez Zea; Luz Adriana Gutiérrez Ramírez; Olga Inés Montoya Campuzano

    2014-01-01

    Resumen. En los sistemas de crianza intensiva especialmenteen cerdos, la resistencia antimicrobiana de algunas bacteriaspatógenas, se ha convertido en un problema mundial, tantopara los productores como para los consumidores. El uso demicroorganismos probióticos aislados de calostro de cerda criadasen sistemas intensivos han demostrado eficacia en la inhibicióndel crecimiento de algunos patógenos entéricos. Se eligierondos cepas denominadas como BAL1 y BAL3, a las cuales se lesevaluó el poten...

  19. Características de frutos de pimentão pulverizados com produtos de ação bactericida Characteristics of bell pepper fruits affected by products with bactericidal action

    Directory of Open Access Journals (Sweden)

    Mariella C Rocha

    2006-06-01

    Full Text Available Muitas das tecnologias desenvolvidas para a cultura do pimentão estão voltadas para a melhoria da produtividade e da aparência dos frutos sem considerar aspectos como sabor, valor nutricional e resíduos tóxicos remanescentes. O presente trabalho teve como objetivos avaliar o efeito de pulverizações semanais com biofertilizante Agrobio (5%, oxicloreto de cobre (2,4 g L-1, sulfato de estreptomicina + oxitetraciclina (0,8 g L-1 e testemunha (água, sobre a produtividade e a qualidade de frutos de três cultivares de pimentão: Magda, Cascadura Itaipu e o híbrido Magali R. Adotou-se o delineamento de blocos ao acaso com quatro repetições, em esquema fatorial (4x3. As variáveis analisadas foram produtividade, características físicas e físico-químicas, teor e acúmulo de fósforo, cobre e chumbo nos frutos. Observou-se maior diâmetro longitudinal e volume dos frutos e maiores produtividade e eficiência no aproveitamento do fósforo pelo híbrido 'Magali R'. Observaram-se diferenças entre as cultivares quanto à taxa de acúmulo de cobre nos frutos, tendo sido quatro vezes maior em frutos de "Magda" pulverizados com oxicloreto de cobre que nos demais tratamentos e, nenhum efeito dos tratamentos sobre o acúmulo de chumbo. Os teores de cobre e chumbo encontrados, porém, estão dentro da faixa aceitável pela Anvisa. Constatou-se, ainda, que as aplicações de cobre afetam o sabor dos frutos, principalmente por influenciar em sua acidez total titulável, expressa em maiores teores de ácido cítrico e menores valores de pH. Os resultados apontam, ainda, para uma relação entre acúmulo de cobre nos frutos e eficiência do uso de fósforo, sendo, porém, necessários novos estudos para sua comprovação.Most technologies used for bell pepper production emphasize yields, shape and size of the fruits, with less attention to features such as flavor, nutritional value and toxic residue content. The objectives of the present work, accomplished in field and laboratory conditions, were to evaluate the effect of weekly sprayings of Agrobio biofertilizer (5%v.v., copper oxychloride (2.4 g active ingredient L-1, streptomycin sulphate + oxitetracycline (0.8% active ingredient L-1 and water as control treatment, on the production and quality of fruits of three cultivars of bell peppers: "Magda", "Cascadura Itaipu" and "Magali R". In both conditions, a randomized complete block design with four replicates was used, in a factorial scheme (4x3. The analyzed variables were productivity, physical and physical-chemical features, percentage and total P, Cu and Pb in fruits. Larger longitudinal diameter and volume as well as higher productivity and efficiency of P use by 'Magali R' were found. There was no effect of the treatments on Pb accumulation but effects were found on Cu. Higher Cu concentrations were found in fruits treated with copper oxychloride, especially in cultivar ' Magda', although concentrations found were within the range acceptable by the national sanitary agency (ANVISA parameters. Besides, Cu applications afffected fruit flavor, primarily by changing total titrable acidity and lower pH. Results also suggested a relationship of Cu content and P efficiency use by pepper plants, which need further confirmation.

  20. Aqueous-phase chemistry and bactericidal effects from an air discharge plasma in contact with water: evidence for the formation of peroxynitrite through a pseudo-second-order post-discharge reaction of H2O2 and HNO2

    Science.gov (United States)

    Lukes, P.; Dolezalova, E.; Sisrova, I.; Clupek, M.

    2014-02-01

    The formation of transient species (OH·, NO2·, NO radicals) and long-lived chemical products (O3, H2O2, NO_{3}^{-} , NO_{2}^{-} ) produced by a gas discharge plasma at the gas-liquid interface and directly in the liquid was measured in dependence on the gas atmosphere (20% oxygen mixtures with nitrogen or with argon) and pH of plasma-treated water (controlled by buffers at pH 3.3, 6.9 or 10.1). The aqueous-phase chemistry and specific contributions of these species to the chemical and biocidal effects of air discharge plasma in water were evaluated using phenol as a chemical probe and bacteria Escherichia coli. The nitrated and nitrosylated products of phenol (4-nitrophenol, 2-nitrophenol, 4-nitrocatechol, 4-nitrosophenol) in addition to the hydroxylated products (catechol, hydroquinone, 1,4-benzoquinone, hydroxy-1,4-benzoquinone) evidenced formation of NO2·, NO· and OH· radicals and NO+ ions directly by the air plasma at the gas-liquid interface and through post-discharge processes in plasma-activated water (PAW) mediated by peroxynitrite (ONOOH). Kinetic study of post-discharge evolution of H2O2 and NO_{2}^{-} in PAW has demonstrated excellent fit with the pseudo-second-order reaction between H2O2 and NO_{2}^{-} . The third-order rate constant k = 1.1 × 103 M-2 s-1 for the reaction NO_{2}^{-} +H_{2}O_{2}+H^{+}\\to ONOOH+H_{2}O was determined in PAW at pH 3.3 with the rate of ONOOH formation in the range 10-8-10-9 M s-1. Peroxynitrite chemistry was shown to significantly participate in the antibacterial properties of PAW. Ozone presence in PAW was proved indirectly by pH-dependent degradation of phenol and detection of cis,cis-muconic acid, but contribution of ozone to the inactivation of bacteria by the air plasma was negligible.

  1. Visible optical radiation generates bactericidal effect applicable for inactivation of health care associated germs demonstrated by inactivation of E. coli and B. subtilis using 405-nm and 460-nm light emitting diodes

    Science.gov (United States)

    Hönes, Katharina; Stangl, Felix; Sift, Michael; Hessling, Martin

    2015-07-01

    The Ulm University of Applied Sciences is investigating a technique using visible optical radiation (405 nm and 460 nm) to inactivate health-hazardous bacteria in water. A conceivable application could be point-of-use disinfection implementations in developing countries for safe drinking water supply. Another possible application field could be to provide sterile water in medical institutions like hospitals or dental surgeries where contaminated pipework or long-term disuse often results in higher germ concentrations. Optical radiation for disinfection is presently mostly used in UV wavelength ranges but the possibility of bacterial inactivation with visible light was so far generally disregarded. One of the advantages of visible light is, that instead of mercury arc lamps, light emitting diodes could be used, which are commercially available and therefore cost-efficient concerning the visible light spectrum. Furthermore they inherit a considerable longer life span than UV-C LEDs and are non-hazardous in contrast to mercury arc lamps. Above all there are specific germs, like Bacillus subtilis, which show an inactivation resistance to UV-C wavelengths. Due to the totally different deactivation mechanism even higher disinfection rates are reached, compared to Escherichia coli as a standard laboratory germ. By 460 nm a reduction of three log-levels appeared with Bacillus subtilis and a half log-level with Escherichia coli both at a dose of about 300 J/cm². By the more efficient wavelength of 405 nm four and a half log-levels are reached with Bacillus subtilis and one and a half log-level with Escherichia coli also both at a dose of about 300 J/cm². In addition the employed optical setup, which delivered a homogeneous illumination and skirts the need of a stirring technique to compensate irregularities, was an important improvement compared to previous published setups. Evaluated by optical simulation in ZEMAX® the designed optical element provided proven homogeneity distributions with maximum variation of ± 10 %.

  2. Characterization of Diverse Subvariants of the Meningococcal Factor H (fH) Binding Protein for Their Ability To Bind fH, To Mediate Serum Resistance, and To Induce Bactericidal Antibodies

    NARCIS (Netherlands)

    K.L. Seib; B. Brunelli; B. Brogioni; E. Palumbo; S. Bambini; A. Muzzi; F. Dimarcello; S. Marchi; A. van den Ende; B. Aricó; S. Savino; M. Scarselli; M. Comanducci; R. Rappuoli; M.M. Giuliani; M. Pizza

    2011-01-01

    Neisseria meningitidis is a commensal of the human nasopharynx but is also a major cause of septicemia and meningitis. The meningococcal factor H binding protein (fHbp) binds human factor H (fH), enabling down-regulation of complement activation on the bacterial surface. fHbp is a component of two s

  3. 酸性氧化电位水根管冲洗的抗菌效果%Study on the Bactericidal Effect of Root Canals Irrigated with Electrolyzed Oxidizing Water

    Institute of Scientific and Technical Information of China (English)

    刘国勤; 赵海军; 张庆福; 陈俊; 张新海; 刘筠; 陈铁楼

    2007-01-01

    目的:研究酸性氧化电位水超声冲洗杀灭感染根管内厌氧菌的效果及其作为根管超声冲洗液的可行性.方法:将90例慢性根尖周炎患者共90颗患牙随机分为3组,每组各30颗患牙,第1组手持器械结合机用根管锉进行根管预备,常规针管式双氧水与生理盐水交替冲洗,第2、第3组同第一组进行根管预备,分别以生理盐水、酸性氧化电位水作为冲洗液进行根管超声冲洗,根管预备前后分别根管内取样进行厌氧菌培养.结果:第2组厌氧菌减少程度明显大于第1组(P<O.05);第3组厌氧菌减少程度大于第2组(P<O.01)、显著大于第1组(P<O.001).结论:超声波在根管预备方面有一定的优势,酸性氧化电位水配合超声冲洗能有效杀灭感染根管内的厌氧菌,是一种理想的根管超声冲洗消毒液.

  4. Comparison of Triclocarban with Triclosan M W in bactericidal soap%康洁新与特可新在除菌皂中杀菌效果的比较

    Institute of Scientific and Technical Information of China (English)

    李晓敏

    2005-01-01

    康洁新和特可新是两种应用于除菌皂中的主要功效原料.根据其性能、价格,在它们的适宜加入范围内选择同样的功效原料成本,又采用传统生产工艺选择合适的加入方法,然后,用卫生部规定的中的方法对常见的3种菌进行除菌效果检测,结果表明,5 min内加入康洁新的样皂除对绿脓杆菌的杀灭效果为99.80%外,对其余菌种杀灭效果均为100%,其效果优于加入特可新的样皂.

  5. Decreased outer membrane permeability protects mycobacteria from killing by ubiquitin-derived peptides

    OpenAIRE

    Purdy, Georgiana E.; Niederweis, Michael; Russell, David G.

    2009-01-01

    Ubiquitin-derived peptides are bactericidal in vitro and contribute to the mycobactericidal activity of the lysosome. To further define interactions of ubiquitin-derived peptides with mycobacteria, we screened for mutants with increased resistance to the bactericidal activity of the synthetic ubiquitin-derived peptide Ub2. The four Ub2-resistant M. smegmatis mutants were also resistant to the bactericidal action of other antimicrobial peptides and macrophages. Two mutants were in the mspA gen...

  6. The effect of polyhexamethylene guanidine hydrochloride (PHMG) derivatives introduced into polylactide (PLA) on the activity of bacterial enzymes

    OpenAIRE

    Walczak, Maciej; Richert, Agnieszka; Burkowska-But, Aleksandra

    2014-01-01

    The present study was aimed at investigating bactericidal properties of polylactide (PLA) films containing three different polyhexamethylene guanidine hydrochloride (PHMG) derivatives and effect of the derivatives on extracellular hydrolytic enzymes and intracellular dehydrogenases. All PHMG derivatives had a slightly stronger bactericidal effect on Staphylococcus aureus than on E. coli but only PHMG granular polyethylene wax (at the concentration of at least 0.6 %) has a bactericidal effect....

  7. Facile fabrication of rice husk based silicon dioxide nanospheres loaded with silver nanoparticles as a rice antibacterial agent

    OpenAIRE

    Jianghu Cui; You Liang; Desong Yang; Yingliang Liu

    2016-01-01

    Bacterial leaf blight of rice caused by Xanthomonas oryzae pv. oryzae (Xoo) is a major disease of rice, leading to reduction in production by 10–50%. In order to control this disease, various chemical bactericides have been used. Wide and prolonged application of chemical bactericides resulted in the resistant strain of Xoo that was isolated from rice. To address this problem, we were searching for an environmentally friendly alternative to the commonly used chemical bactericides. In this wor...

  8. Biological Characteristics and Screening of Bactericides Against Bacterial Leaf Spot Pathogen on Processing Pepper%加工型辣椒细菌性叶斑病病原菌生物学特性及抑菌药剂筛选

    Institute of Scientific and Technical Information of China (English)

    管晶晶; 张春竹; 罗明; 李克梅; 盛强; 孙翔

    2014-01-01

    研究了新疆加工型辣椒细菌性斑点病病原菌Pseudomonas syringae pv .syringae 的部分生物学特征,并采用室内平板抑菌和盆栽试验对6种杀菌剂的防病效果进行了测定和筛选.结果表明,辣椒细菌性斑点病病原菌最适合生长的培养基为BPA培养基.25~30℃为适宜生长温度,最适温度为28℃.适宜在 pH6.5~8.0环境中生长,最适 pH 值为7.病原菌在1% NaCl浓度下生长良好,大于4% NaCl 生长受抑制.供试药剂的室内平板抑菌效果为:可杀得2000>乙酸铜>链霉素>志信101>红星-2氢氧化铜>志信2000,可杀得2000和乙酸铜的EC50值分别为5.954 mg/L和7.439 mg/L.盆栽试验结果显示,在发病前保护性喷施各药剂的防病效果(43.34%~80.84%)优于发病后治疗性施药(12.35%~49.54%),其中可杀得2000和红星-2氢氧化铜的防治效果较好.%The experiment studied the biological characteristics and evaluation the control effect of several kinds of fungicide against processing pepper bacterial spot disease of Xinjiang.The results showed that Pseudomonas syringae pv.syringae is most suitable for growing medium-BPA medium,growing range of temperature is 25-30 ℃,the optimum temperature was 28 ℃,which grows in pH range of 6.5 to 8.0,the optimal pH value of 7.The pathogen grows well under 1% NaCl,when more than 4% NaCl,its growth was inhibited.Invitro experiment showed that Kocide2000> Copper acetate>Streptomycin>Copper Hydrox-ide101>Cupic Hydroxide> Copper Hydroxide2000.Kocide 2000 and Copper acetate EC50 values were 5.954 mg/L and 7.439 mg/L,Greenhouse tests showed that the control effect of protective spraying (43.34%-80.84%)is better than the control effect of therapeutic spraying(12.35%-49.54%),of which Kocide2000 and Cupic Hydroxide have better control effect.

  9. Structure of complexes of nitrilo tris methylene phosphonic acid with copper, [CuN(CH2PO3)3(H2O)3] and Na4[CuN(CH2PO3)3]2 · 19H2O, as bactericides and inhibitors of scaling and corrosion

    Science.gov (United States)

    Somov, N. V.; Chausov, F. F.

    2015-03-01

    Nitrilotris methylene phosphonate triaqua copper and octasodium bis(nitrilotris methylene phosphonate cuprate(II)) nonadecahydrate have been synthesized and investigated. [CuN(CH2PO3)3(H2O)3] is crystallized in the sp. gr. P21/ c, Z = 4, a = 9.2506(2) Å, b = 15.9815(2) Å, c = 9.5474(2) Å, β = 113.697(2)°. The copper atom is coordinated by oxygen atoms in the configuration of elongated octahedron; the ligand (of bridge type) links neighboring copper atoms. Na8[CuN(CH2PO3)3]2 · 19H2O is crystallized in the sp. gr. P21/ c, Z = 2, a = 11.24550(10) Å, b = 17.38980(10) Å, c = 13.5852(2) Å, β = 127.8120(10)°. This complex is chelating; the copper atom closes three five-membered N-C-P-O-Cu cycles with a shared Cu-N bond. Copper is coordinated in a distorted trigonal-bipyramidal configuration.

  10. In vitro bactericidal activity of equine platelet concentrates, platelet poor plasma, and plasma against methicillin-resistant Staphylococcus aureus Actividad bactericida in vitro de concentrados de plaquetas, plasma pobre en plaquetas y plasma de equinos contra Staphylococcus aureus resistente a la meticilina

    Directory of Open Access Journals (Sweden)

    ME Álvarez

    2011-01-01

    Full Text Available The aims of the study were 1 to evaluate the antibacterial effect of equine platelet concentrates (ePCs (either activated or not with calcium gluconate (CG against methicillin-resistant Staphylococcus aureus (MRSA, and 2 to compare their antibacterial effect with activated platelet poor plasma (PPP and plasma (P. Blood products were allotted in 4 groups (ePC, ePC/CG, PPP/CG, and P plus a positive control group (PCG and a negative control group, and mixed with MRSA and Mueller-Hinton broth. Samples were incubated during 1, 4, 8, 12, and 24 h, and colony-forming units were counted. The bacterial growth was significantly (P = 0.01 inhibited by the ePC, ePC/CG, PPP/CG and P in comparison with the PCG during the first 12 h. At 24h only a statistically significant (P = 0.01 antibacterial effect was noticed for the ePC, ePC/ CG and PPP/CG in comparison with the PCG and P. Equine PCs and PPP provided the best in vitro antibacterial effect against MRSA.Los objetivos del estudio fueron: 1 evaluar el efecto antibacteriano de concentrados de plaquetas equinas (ePC (activados o no con gluconato de calcio (CG frente a Staphylococcus aureus meticilino-resistente (MRSA y 2 comparar su efecto antibacteriano contra plasma pobre en plaquetas (PPP (activado con CG -PPP/GC- y plasma (P. Los productos sanguíneos fueron divididos en 4 grupos (ePC, ePC/CG, PPP/CG y P, más un grupo control positivo (PCG y otro control negativo. Los grupos se mezclaron con caldo Mueller-Hinton y MRSA. Las muestras fueron incubadas durante 1, 4, 8, 12 y 24 horas y se contaron las unidades formadoras de colonias. El crecimiento de las bacterias fue significativamente (P = 0,01 inhibido por el ePC, ePC/CG, PPP/CG y P en comparación con el PCG durante las primeras 12 h. Sólo a las 24 horas hubo una diferencia estadísticamente significativa (P = 0.01 y se observó un efecto antibacteriano para el ePC, ePC/CG y PPP/CG en comparación con el PCG y P. Los ePCs y PPP equinos mostraron el mejor efecto antibacteriano in vitro contra el MRSA.

  11. Atividade bacteriostática e bactericida do decocto de Baccharis trimera (Less.) D.C., Compositae, carqueja, como desinfetante ou anti-séptico Bacteriostatic and bactericidal activity of the Baccharis trimera (Less.) D.C. - Compositae decocto, as disinfectant or antisseptic

    OpenAIRE

    C.A.M. Avancini; J.M. Wiest; E. Mundstock

    2000-01-01

    Verificou-se a atividade antimicrobiana in vitro do decocto de Baccharis trimera (Less) D.C., Compositae, (carqueja) por meio de testes-padrão internacionais utilizados para avaliar desinfetantes e anti-sépticos. Determinaram-se a concentração inibitória mínima e a concentração bactericida mínima do decocto frente a várias diluições de inóculos. Os resultados sugerem a possibilidade de se utilizar o decocto de B. trimera como desinfetante e anti-séptico em determinadas situações-problema em p...

  12. Tetrahydropyrazolo[1,5-a]pyrimidine-3-carboxamide and N-benzyl-6',7'-dihydrospiro[piperidine-4,4'-thieno[3,2-c]pyran] analogues with bactericidal efficacy against Mycobacterium tuberculosis targeting MmpL3.

    Directory of Open Access Journals (Sweden)

    Modesto J Remuiñán

    Full Text Available Mycobacterium tuberculosis is a major human pathogen and the causative agent for the pulmonary disease, tuberculosis (TB. Current treatment programs to combat TB are under threat due to the emergence of multi-drug and extensively-drug resistant TB. As part of our efforts towards the discovery of new anti-tubercular leads, a number of potent tetrahydropyrazolo[1,5-a]pyrimidine-3-carboxamide (THPP and N-benzyl-6',7'-dihydrospiro[piperidine-4,4'-thieno[3,2-c]pyran] (Spiro analogues were recently identified against Mycobacterium tuberculosis and Mycobacterium bovis BCG through a high-throughput whole-cell screening campaign. Herein, we describe the attractive in vitro and in vivo anti-tubercular profiles of both lead series. The generation of M. tuberculosis spontaneous mutants and subsequent whole genome sequencing of several resistant mutants identified single mutations in the essential mmpL3 gene. This 'genetic phenotype' was further confirmed by a 'chemical phenotype', whereby M. bovis BCG treated with both the THPP and Spiro series resulted in the accumulation of trehalose monomycolate. In vivo efficacy evaluation of two optimized THPP and Spiro leads showed how the compounds were able to reduce >2 logs bacterial cfu counts in the lungs of infected mice.

  13. AcEST: DK949606 [AcEST

    Lifescience Database Archive (English)

    Full Text Available |GNL3_CAEEL Guanine nucleotide-binding protein-like 3 h... 37 0.099 sp|P17453|BPI_BOVIN Bactericidal permeability...RRKACNVGNLPGITKEIQ--EVELDKNIRLIDSPGVILVSQKDLD-PIEVALKNAIR 334 >sp|P17453|BPI_BOVIN Bactericidal permeability

  14. AcEST: DK959594 [AcEST

    Lifescience Database Archive (English)

    Full Text Available D1 OS=Ashbya gossypi... 31 4.9 sp|P17213|BPI_HUMAN Bactericidal permeability-increasing protein... 31 4.9 sp...|Q9Y3L3|3BP1_HUMAN SH3 domain-binding protein 1 OS=Homo sapien... 31 4.9 sp|P17453|BPI_BOVIN Bactericidal permeability...r|Q804Q9|Q804Q9_CYPCA Bactericidal permeability-increasing prot... 46 0.002 tr|Q6...protein OS=Xenopus laevis GN... 43 0.014 tr|Q4KTY6|Q4KTY6_ICTPU Bactericidal permeability-increasing prot......ive uncharacterized protein OS=Chaet... 38 0.46 tr|Q7T3Q9|Q7T3Q9_GADMO Bactericidal permeability increasing

  15. AcEST: DK961979 [AcEST

    Lifescience Database Archive (English)

    Full Text Available ... 40 0.014 sp|P39712|FLO9_YEAST Flocculation protein FLO9 OS=Saccharomyces ... 34 0.59 sp|P17213|BPI_HUMAN Bactericidal permeabilit...y-increasing protein... 34 0.59 sp|Q8NFQ6|BPIL2_HUMAN Bactericidal/permeability-inc...reasing prote... 34 0.59 sp|P17453|BPI_BOVIN Bactericidal permeability-increasing...+SP + +S+ L Sbjct: 974 SSSSISSESPKSTYSSSSL 992 >sp|P17213|BPI_HUMAN Bactericidal permeability-increasing pro... >sp|Q8NFQ6|BPIL2_HUMAN Bactericidal/permeability-increasing protein-like 2 OS=Homo sapiens GN=BPIL2 PE=1 SV

  16. Enzymatic removal and disinfection of bacterial biofilms

    DEFF Research Database (Denmark)

    Johansen, Charlotte; Falholt, Per; Gram, Lone

    1997-01-01

    -coated hydroxyapatite. The activity of enzymes against bacterial cells in biofilm was measured by fluorescence microscopy and an indirect conductance test in which evolution of carbon dioxide was measured. Glucose oxidase combined with lactoperoxidase was bactericidal against biofilm bacteria but did not remove the...... biofilm from the substrata. A complex mixture of polysaccharide-hydrolyzing enzymes was able to remove bacterial biofilm from steel and polypropylene substrata but did not have a significant bactericidal activity. Combining oxidoreductases with polysaccharide-hydrolyzing enzymes resulted in bactericidal...

  17. Take Your Medicines Safely

    Medline Plus

    Full Text Available ... better, the antibiotic is working in killing the bacteria, but it might not completely give what they call a "bactericidal effect." That means taking the bacteria completely out of the system. It might be ...

  18. A survey of phytotoxic microbial and plant metabolites as potential natural products for pest management

    Science.gov (United States)

    Phytotoxic microbial metabolites produced by certain phytopathogenic fungi and bacteria and a group of a phytotoxic plant metabolites including Amayllidaceae alkaloids and some derivatives of these compounds were evaluated for algicide, bactericide, insecticide, fungicide, and herbicide activities i...

  19. Chemical composition of water extracts from shungite and shungite water

    International Nuclear Information System (INIS)

    Chemical analysis of water extracts from shungite-3 of Zagozhino deposit (Karelia) and natural water contacting with shungite rocks are done. Chemical composition and bactericide properties of shungite water are studied

  20. Potential antibiotic and anti-infective effects of rhodomyrtone from Rhodomyrtus tomentosa (Aiton) Hassk. on Streptococcus pyogenes as revealed by proteomics

    NARCIS (Netherlands)

    Limsuwan, Surasak; Voravuthikunchai, Supayang Piyawan; van Dijl, Jan Maarten; Kayser, Oliver; Meinders, Hesseling A.

    2011-01-01

    Rhodomyrtone from Rhodomyrtus tomentosa (Aiton) Hassk. leaf extract has a strong antibacterial activity against the bacterial pathogen Streptococcus pyogenes. Our previous studies indicated that the bactericidal activity of rhodomyrtone might involve intracellular targets. In the present studies we

  1. Take Your Medicines Safely

    Medline Plus

    Full Text Available ... the bacteria, but it might not completely give what they call a "bactericidal effect." That means taking ... be sure to ask the following six questions-- What is the name of the medicine? What is ...

  2. Take Your Medicines Safely

    Medline Plus

    Full Text Available ... give what they call a "bactericidal effect." That means taking the bacteria completely out of the system. ... I find they sell over-the-counter aids-- little plastic containers with the days of the week ...

  3. Arabidopsis CDS blastp result: AK103132 [KOME

    Lifescience Database Archive (English)

    Full Text Available similarity to SP|P17213 Bactericidal permeability-increasing protein precursor (BPI) {Homo sapiens}; contains Pfam profile PF02886: LBP / BPI / CETP family, C-terminal domain 1e-91 ...

  4. MICs and MBCs of chemotherapeutic agents against Renibacterium salmoninarum.

    Science.gov (United States)

    Bandín, I; Santos, Y; Toranzo, A E; Barja, J L

    1991-05-01

    The efficacies of 21 chemotherapeutic agents for controlling bacterial kidney disease were evaluated. The bactericidal and/or bacteriostatic effects of these drugs were tested against 11 Renibacterium salmoninarum strains with different origins. The most effective compounds displaying both bacteriostatic and bactericidal activity for all the isolates were tetracycline and erythromycin, with MICs ranging from less than 0.62 to 10.95 micrograms/ml for tetracycline and from less than 0.62 to 5.47 micrograms/ml for erythromycin. Whereas tetracycline showed identical MICs and MBCs, erythromycin showed bactericidal effects at concentrations of 5.47 to 21.87 micrograms/ml. Similarly, cefazolin and tiamulin proved to be very effective bactericidal compounds against the majority of R. salmoninarum isolates, with MBCs for 90% of the strains tested of 21.87 and 10.95 micrograms/ml, respectively. Neither nitrofuranes, quinolones, nor sulfonamides showed inhibitory effects on the growth of the strains. PMID:1854157

  5. Antimicrobial peptide melittin against Xanthomonas oryzae pv. oryzae, the bacterial leaf blight pathogen in rice

    OpenAIRE

    SHI, Wei; Li, Caiyun; Li, Man; Zong, Xicui; Han, Dongju; Chen, Yuqing

    2016-01-01

    Xanthomonas oryzae pv. oryzae is a destructive bacterial disease of rice, and the development of an environmentally safe bactericide is urgently needed. Antimicrobial peptides, as antibacterial sources, may play important roles in bactericide development. In the present study, we found that the antimicrobial peptide melittin had the desired antibacterial activity against X. oryzae pv. oryzae. The antibacterial mechanism was investigated by examining its effects on cell membranes, energy metab...

  6. Comparison of Six Generic Vancomycin Products for Treatment of Methicillin-Resistant Staphylococcus aureus Experimental Endocarditis in Rabbits

    OpenAIRE

    Tattevin, P.; Saleh-Mghir, A.; Davido, B.; Ghout, I.; Massias, L; Garcia de la Maria, C.; Miró, J M; Perronne, C.; Laurent, F.; Crémieux, A. C.

    2013-01-01

    Concerns have recently emerged about the potency and the quality of generic vancomycin (VAN) products approved for use in humans, based on experiments in a neutropenic mouse thigh infection model. However, other animal models may be more appropriate to decipher the bactericidal activities of VAN generics in vivo and to predict their efficacy in humans. We aimed to compare the bactericidal activities of six generic VAN products currently used in France (Mylan and Sandoz), Spain (Hospira), Swit...

  7. High Therapeutic Index of Factor C Sushi Peptides: Potent Antimicrobials against Pseudomonas aeruginosa

    OpenAIRE

    Yau, Yin Hoe; Ho, Bow; Tan, Nguan Soon; Ng, Miang Lon; Ding, Jeak Ling

    2001-01-01

    Factor C protein isolated from the horseshoe crab, Carcinoscorpius rotundicauda, has endotoxin binding capability. Synthetic peptides of 34 amino acids based on the sequence of two regions of factor C (Sushi 1 and Sushi 3) as well as their corresponding mutants exhibited activities against 30 clinical isolates of Pseudomonas aeruginosa. Collectively, all four peptides demonstrated exceptionally effective bactericidal activity against P. aeruginosa with 90% minimal bactericidal concentrations ...

  8. In vitro activity of amoxicillin in combination with clavulanic acid against Mycobacterium tuberculosis.

    OpenAIRE

    Cynamon, M H; Palmer, G S

    1983-01-01

    The comparative in vitro activity of amoxicillin alone and in combination with clavulanic acid against 15 isolates of Mycobacterium tuberculosis was evaluated by broth dilution susceptibility testing. Amoxicillin inhibited 4 of 15 isolates at 8 micrograms/ml or less but was not bactericidal against any of the isolates at that concentration. Amoxicillin in combination with clavulanic acid was bactericidal for 14 of 15 isolates tested at an amoxicillin concentration of 4 micrograms/ml or less a...

  9. PA-824 Exhibits Time-Dependent Activity in a Murine Model of Tuberculosis▿

    OpenAIRE

    Ahmad, Zahoor; Peloquin, Charles A.; Singh, Rajendra P.; Derendorf, Hartmut; Tyagi, Sandeep; Ginsberg, Ann; Jacques H Grosset; Eric L Nuermberger

    2010-01-01

    PA-824 is one of two nitroimidazoles in phase II clinical trials to treat tuberculosis. In mice, it has dose-dependent early bactericidal and sterilizing activity. In humans with tuberculosis, PA-824 demonstrated early bactericidal activity (EBA) at doses ranging from 200 to 1,200 mg per day, but no dose-response effect was observed. To better understand the relationship between drug exposure and effect, we performed a dose fractionation study in mice. Dose-ranging pharmacokinetic data were u...

  10. Activity of telavancin compared to other agents against coagulase-negative staphylococci with different resistotypes by time kill.

    Science.gov (United States)

    Lin, Gengrong; Pankuch, Glenn A; Appelbaum, Peter C; Kosowska-Shick, Klaudia

    2012-07-01

    Among 10 coagulase-negative staphylococci, telavancin, quinupristin/dalfopristin, and tigecycline were the most potent antimicrobials. Telavancin exhibited bactericidal effect to 9 strains out of 10 tested at 4× MIC after 24 h of exposure similar to those of vancomycin and daptomycin. By contrast, linezolid was mainly bacteriostatic and teicoplanin was bactericidal to 7 strains tested at 4× MIC after 24 h. PMID:22575272

  11. Influence of Physical and Chemical Modification on the Optical Rotatory Dispersion and Biological Activity of Chitosan Films

    Directory of Open Access Journals (Sweden)

    A. B. Shipovskaya

    2013-01-01

    Full Text Available The optical and bactericidal properties of acetic and basic chitosan films were studied. By the ORD technique, we found that these films differed in the values of their specific optical rotation and of their rotary and dispersive constants. A sign inversion of was observed when the acetic chitosan films were heat-treated. The bactericidal activity of the initial and dehydrated acetic films was analyzed, and their moisture content and optical and biological activities were compared.

  12. Activities of new quinoline derivatives against genital pathogens.

    OpenAIRE

    AZNAR;, J.; Caballero, M C; Lozano, M C; Miguel, C. de; Palomares, J C; Perea, E J

    1985-01-01

    The in vitro activities of four quinoline carboxylic acids against 48 strains of Neisseria gonorrhoeae, 10 of Chlamydia trachomatis, and 32 of Ureaplasma urealyticum were compared. Ciprofloxacin was the most active against N. gonorrhoeae and C. trachomatis but had poor bactericidal activity against U. urealyticum, whereas ofloxacin showed the most bactericidal activity against U. urealyticum but was less active than ciprofloxacin against the two former pathogens. Norfloxacin and enoxacin were...

  13. Differential Complement Resistance Mediates Virulence of Haemophilus influenzae Type b

    OpenAIRE

    Sutton, Ann; Schneerson, Rachel; Kendall-Morris, Saundra; Robbins, John B.

    1982-01-01

    Studies were undertaken to gain insight into the virulence of type b in contrast to the other Haemophilus influenzae capsular types. A relationship was found between the comparative virulence of H. influenzae types in humans and their resistance to the bactericidal effect of antibody-free complement. Type b was most resistant to the bactericidal effect of complement. The other types could be divided into three groups based upon their susceptibility to complement; this grouping was also relate...

  14. Influence of presowing laser and gamma irradiation on the cucumber resistance to angular spots (Pseudomonas lachrymas)

    International Nuclear Information System (INIS)

    The bactericide effect of two beams against the angular spots agent (Pseudomonas lachrymans) by the plants developed from infected seeds and by the artificially infected plants developed from uncontaminated seeds was studied, it was established that as a result of irradiation the field germination of contaminated seeds has been increased as the activity of some respiratory enzymes in the leaves. At two variants of infection degree of attack became smaller. The bactericide effect was better revealed at the combination laser+gamma rays

  15. Mechanism of Enhanced Activity of Liposome-Entrapped Aminoglycosides against Resistant Strains of Pseudomonas aeruginosa

    OpenAIRE

    Mugabe, Clement; Halwani, Majed; Azghani, Ali O.; Lafrenie, Robert M.; Omri, Abdelwahab

    2006-01-01

    Pseudomonas aeruginosa is inherently resistant to most conventional antibiotics. The mechanism of resistance of this bacterium is mainly associated with the low permeability of its outer membrane to these agents. We sought to assess the bactericidal efficacy of liposome-entrapped aminoglycosides against resistant clinical strains of P. aeruginosa and to define the mechanism of liposome-bacterium interactions. Aminoglycosides were incorporated into liposomes, and the bactericidal efficacies of...

  16. Involvement of penicillin-binding protein 2 with other penicillin-binding proteins in lysis of Escherichia coli by some beta-lactam antibiotics alone and in synergistic lytic effect of amdinocillin (mecillinam).

    OpenAIRE

    Gutmann, L; Vincent, S; Billot-Klein, D; Acar, J F; Mrèna, E; Williamson, R.

    1986-01-01

    Compared with cefotaxime, ceftazidime, moxalactam, and aztreonam, ceftriaxone produced the best lytic and bactericidal effects when each was added at about 10 times the MIC to Escherichia coli W7. When each of these antibiotics was added at its MIC, only bacteriostasis occurred, but the simultaneous addition of amdinocillin (mecillinam) was synergistic in causing rapid lysis and bactericidal effects. Induction of lysis of two E. coli mutants containing either a thermosensitive penicillin-bind...

  17. A bacteriological survey of sanitary dressings, and development of an effective means for their disposal.

    OpenAIRE

    Lucas, C M; Mendes, M. F.

    1980-01-01

    A microbiological survey of over 400 sanitary dressings is reported: large numbers of bacteria are present, including species indicative of faecal contamination. The need for an effective bactericide in chemical bin exchange systems is thus demonstrated. Screening trials of several candidate formulations have been undertaken: buffered sodium metabisulphite, releasing sulphur dioxide as a vapour-phase bactericide, has now been introduced as an effective bin exchnage system.

  18. Antibacterial activity of vegetal extracts against serovars of Salmonella Atividade antibacteriana de extratos vegetais sobre sorovares de Salmonella

    OpenAIRE

    Daiane Voss-Rech; Cátia Silene Klein; Vânia Helena Techio; Gerson Neudi Scheuermann; Gilberto Rech; Laurimar Fiorentin

    2011-01-01

    in vitro antibacterial activity of 21 hydroethanolic vegetal extracts was assessed against 20 serovars of Salmonella. Regarding the tested extracts, 85.7% of them presented antibacterial activity. The six active extracts which showed activity on the largest number of serovars and the extract of Eucalyptus sp. were submitted to the determination of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Of these, six extracts showed bacteriostatic and bactericidal ...

  19. Effects of Oakmoss and Its Components on Biofilm Formation of Legionella pneumophila

    OpenAIRE

    野村, 陽恵; 一色, 恭徳; Sakuda, Keisuke; 佐久間, 克也; 近藤, 誠一

    2013-01-01

    Oakmoss and its components are known as antibacterial agents, specifically against Legionella pneumophila. In the present study, we investigated the effects of oakmoss and its components (phenol, didepside and isochromen derivatives) on L. pneumophila biofilm formation, with particular reference to the bactericidal activity (minimum bactericidal concentration; MBC) of these components against the bacterial cells in the biofilm. Of the 20 compounds tested, two didepside derivatives and four ph...

  20. Photo-irradiation of proanthocyanidin as a new disinfection technique via reactive oxygen species formation.

    Directory of Open Access Journals (Sweden)

    Keisuke Nakamura

    Full Text Available In the present study, the bactericidal effect of photo-irradiated proanthocyanidin was evaluated in relation to reactive oxygen species formation. Staphylococcus aureus suspended in proanthocyanidin aqueous solution was irradiated with light from a laser at 405 nm. The bactericidal effect of photo-irradiated proanthocyanidin depended on the concentration of proanthocyanidin, the laser irradiation time, and the laser output power. When proanthocyanidin was used at the concentration of 1 mg/mL, the laser irradiation of the bacterial suspension could kill the bacteria with a >5-log reduction of viable cell counts. By contrast, bactericidal effect was not observed when proanthocyanidin was not irradiated. In electron spin resonance analysis, reactive oxygen species, such as hydroxyl radicals, superoxide anion radicals, and hydrogen peroxide, were detected in the photo-irradiated proanthocyanidin aqueous solution. The yields of the reactive oxygen species also depended on the concentration of proanthocyanidin, the laser irradiation time, and the laser output power as is the case with the bactericidal assay. Thus, it is indicated that the bactericidal effect of photo-irradiated proanthocyanidin is exerted via the reactive oxygen species formation. The bactericidal effect as well as the yield of the oxygen radicals increased with the concentration of proanthocyanidin up to 4 mg/mL, and then decreased with the concentration. These findings suggest that the antioxidative activity of proanthocyanidin might prevail against the radical generation potency of photo-irradiated proanthocyanidin resulting in the decreased bactericidal effect when the concentration is over 4 mg/mL. The present study suggests that photo-irradiated proanthocyanidin whenever used in an optimal concentration range can be a new disinfection technique.

  1. Inhibition of bacterial growth by different mixtures of propofol and thiopentone

    Directory of Open Access Journals (Sweden)

    K.E. Joubert

    2005-06-01

    Full Text Available Propofol is, as a result of its formulation, an ideal bacterial and yeast culture medium. An outbreak of sepsis in humans and an increase in wound infections in dogs has been ascribed to the use of propofol. It has been previously reported that a 1:1 mixture of propofol and thiopentone has bactericidal properties. This study was undertaken to determine if further serial mixtures of propofol and thiopentone maintained the bactericidal properties. Mixtures of 1:1 (solution A, 5:1 (solution B, 10:1 (solution C, 50:1 (solution D and 100:1 (solution E of 1 % propofol to 2.5 % thiopentone, 2.5 % thiopentone (solution T, 1 % propofol (solution P and saline (solution S were prepared and inoculated with between 105 and 106 colony-forming units of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. A sample was withdrawn from each solution at 0, 1, 6, 12, 48 and 120 hours after inoculation and a bacterial count was performed. This study showed that thiopentone and solution A behaved in similar fashion by inhibiting bacterial growth and was bactericidal after 48 hours. Solution B was not bactericidal against S. aureus and C. albicans. Propofol and solutions D and E all supported growth of all the organisms tested. These data indicate that mixtures of propofol and thiopentone at a ratio less than 1:1 do not maintain the bactericidal properties.

  2. Urease from Helicobacter pylori is inactivated by sulforaphane and other isothiocyanates.

    Science.gov (United States)

    Fahey, Jed W; Stephenson, Katherine K; Wade, Kristina L; Talalay, Paul

    2013-05-24

    Infections by Helicobacter pylori are very common, causing gastroduodenal inflammation including peptic ulcers, and increasing the risk of gastric neoplasia. The isothiocyanate (ITC) sulforaphane [SF; 1-isothiocyanato-4-(methylsulfinyl)butane] derived from edible crucifers such as broccoli is potently bactericidal against Helicobacter, including antibiotic-resistant strains, suggesting a possible dietary therapy. Gastric H. pylori infections express high urease activity which generates ammonia, neutralizes gastric acidity, and promotes inflammation. The finding that SF inhibits (inactivates) urease (jack bean and Helicobacter) raised the issue of whether these properties might be functionally related. The rates of inactivation of urease activity depend on enzyme and SF concentrations and show first order kinetics. Treatment with SF results in time-dependent increases in the ultraviolet absorption of partially purified Helicobacter urease in the 260-320 nm region. This provides direct spectroscopic evidence for the formation of dithiocarbamates between the ITC group of SF and cysteine thiols of urease. The potencies of inactivation of Helicobacter urease by isothiocyanates structurally related to SF were surprisingly variable. Natural isothiocyanates closely related to SF, previously shown to be bactericidal (berteroin, hirsutin, phenethyl isothiocyanate, alyssin, and erucin), did not inactivate urease activity. Furthermore, SF is bactericidal against both urease positive and negative H. pylori strains. In contrast, some isothiocyanates such as benzoyl-ITC, are very potent urease inactivators, but are not bactericidal. The bactericidal effects of SF and other ITC against Helicobacter are therefore not obligatorily linked to urease inactivation, but may reduce the inflammatory component of Helicobacter infections. PMID:23583386

  3. Antibacterial properties of chicken intestinal phospholipase A2

    Directory of Open Access Journals (Sweden)

    Gargouri Youssef

    2011-01-01

    Full Text Available Abstract Background The presence of chicken group-IIA PLA2 (ChPLA2-IIA in the intestinal secretion suggests that this enzyme plays an important role in systemic bactericidal defence. We have analyzed the bactericidal activity of purified ChPLA2-IIA, on several gram-positive and gram-negative bacteria by using the diffusion well and dilution methods. Results ChPLA2-IIA displays potent bactericidal activity against gram-positive bacteria but lacks bactericidal activity against gram negative ones. We have also demonstrated a synergic action of ChPLA2-IIA with lysozyme when added to the bacteria culture prior to ChPLA2-IIA. The bactericidal efficiency of ChPLA2-IIA was shown to be dependent upon the presence of calcium ions and then a correlation could be made to its hydrolytic activity of membrane phospholipids. Interestingly ChPLA2-IIA displays a higher dependence to Ca2+ ions than to Mg2+ions. Conclusion We conclude that the main physiological role of ChPLA2-IIA could be the defence of the intestine against bacterial invasions.

  4. Effects of oakmoss and its components on biofilm formation of Legionella pneumophila.

    Science.gov (United States)

    Nomura, Harue; Isshiki, Yasunori; Sakuda, Keisuke; Sakuma, Katsuya; Kondo, Seiichi

    2013-01-01

    Oakmoss and its components are known as antibacterial agents, specifically against Legionella pneumophila. In the present study, we investigated the effects of oakmoss and its components (phenol, didepside and isochromen derivatives) on L. pneumophila biofilm formation, with particular reference to the bactericidal activity (minimum bactericidal concentration; MBC) of these components against the bacterial cells in the biofilm. Of the 20 compounds tested, two didepside derivatives and four phenol derivatives reduced biofilm formation by more than 50% of that observed for the control at their respective minimum inhibitory concentrations (1/2×MIC). The inhibitory activities of these compounds were either equivalent to or greater than that of the clarithromycin reference. Isochromen derivatives had no effect on biofilm formation. Analysis of bactericidal activity of didepside and isochromen derivatives revealed that three of four didepside derivatives and one of four isochromen derivatives exhibited high bactericidal activity (MBC: 32.0-74.7 µg/mL) against the L. pneumophila in the biofilm after 24 h or 48 h of co-incubation; the antibacterial activities of these compounds were almost equivalent to clarithromycin and chlorhexidine gluconate (MBC: 42.7-64.0 µg/mL) that were used as references. Thus, based on their anti-biofilm forming and bactericidal activities, didepside derivatives are considered to be good candidates for disinfectants against L. pneumophila. PMID:23649339

  5. Enzymatic removal and disinfection of bacterial biofilms

    DEFF Research Database (Denmark)

    Johansen, Charlotte; Falholt, Per; Gram, Lone

    1997-01-01

    Model biofilms of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas fluorescens, and Pseudomonas aeruginosa were made on steel and polypropylene substrata. Plaque-resembling biofilms of Streptococcus mutans, Actinomyces, viscosus, and Fusobacterium nucleatum were made on saliva......-coated hydroxyapatite. The activity of enzymes against bacterial cells in biofilm was measured by fluorescence microscopy and an indirect conductance test in which evolution of carbon dioxide was measured. Glucose oxidase combined with lactoperoxidase was bactericidal against biofilm bacteria but did not remove the...... biofilm from the substrata. A complex mixture of polysaccharide-hydrolyzing enzymes was able to remove bacterial biofilm from steel and polypropylene substrata but did not have a significant bactericidal activity. Combining oxidoreductases with polysaccharide-hydrolyzing enzymes resulted in bactericidal...

  6. How about food irradiation? Its history and usefulness. (3) Irradiation effects on food and decrease in fungi

    International Nuclear Information System (INIS)

    Inhibiting germination of vegetables and grade control of maturity of fruits, destroy of insect pest and parasite, disinfection of meats and fishes, bactericidal action of dry foods such as spices, and taste and color change of irradiated foods and perfect bactericidal action are stated. Application of food irradiation contains inhibiting germination, insecticidal action, sterilization of insect pest, grade control of maturity, inhibition of food poisoning, decrease in fungi, improvement of properties, and perfect bactericidal action. Each treatment of foods is described by the effects of three exposure doses such as the low exposure dose until 1 kGy, middle exposure dose from 1 to 10 kGy and high from 10 to 75 kGy. (S.Y.)

  7. Activity of ceftobiprole compared with those of other agents against Staphylococcus aureus strains with different resistotypes by time-kill analysis.

    Science.gov (United States)

    Lin, Gengrong; Appelbaum, Peter C

    2008-02-01

    Among 10 hospital- and community-acquired Staphylococcus aureus strains with differing methicillin and vancomycin resistotypes, all strains were susceptible to ceftobiprole at MICs quinupristin/dalfopristin. Ceftobiprole, at 4x MIC, was bactericidal (99.9% killing) against 9 of 10 strains tested at 4x MIC after 24 h. Ceftobiprole also yielded significant activity at earlier periods, with 90% killing of all strains at 2x MIC at 6 and 12 h. Vancomycin was bactericidal against 6 of 8 strains tested at 2x MIC after 24 h. By contrast, linezolid and tigecycline were mainly bacteriostatic, and quinupristin/dalfopristin was bactericidal against 4 of 10 strains at 2x MIC after 24 h. PMID:17997257

  8. Quantitative evaluation of dermatological antiseptics.

    Science.gov (United States)

    Leitch, C S; Leitch, A E; Tidman, M J

    2015-12-01

    Topical antiseptics are frequently used in dermatological management, yet evidence for the efficacy of traditional generic formulations is often largely anecdotal. We tested the in vitro bactericidal activity of four commonly used topical antiseptics against Staphylococcus aureus, using a modified version of the European Standard EN 1276, a quantitative suspension test for evaluation of the bactericidal activity of chemical disinfectants and antiseptics. To meet the standard for antiseptic effectiveness of EN 1276, at least a 5 log10 reduction in bacterial count within 5 minutes of exposure is required. While 1% benzalkonium chloride and 6% hydrogen peroxide both achieved a 5 log10 reduction in S. aureus count, neither 2% aqueous eosin nor 1 : 10 000 potassium permanganate showed significant bactericidal activity compared with control at exposure periods of up to 1 h. Aqueous eosin and potassium permanganate may have desirable astringent properties, but these results suggest they lack effective antiseptic activity, at least against S. aureus. PMID:26456933

  9. Structural and functional characterization of the conserved salt bridge in mammalian paneth cell alpha-defensins

    DEFF Research Database (Denmark)

    Rosengren, K Johan; Daly, Norelle L; Fornander, Liselotte M;

    2006-01-01

    )-Crp4 peptide, in which a conserved Glu(15) residue was replaced by Asp. Structural analysis of the two peptides confirms the involvement of this Glu in a conserved salt bridge that is removed in the mutant because of the shortened side chain. Despite disruption of this structural feature, the peptide...... variant retains a well defined native fold because of a rearrangement of side chains, which result in compensating favorable interactions. Furthermore, salt bridge-deficient Crp4 mutants were tested for bactericidal effects and resistance to proteolytic degradation, and all of the variants had similar...... bactericidal activities and stability to proteolysis. These findings support the conclusion that the function of the conserved salt bridge in Crp4 is not linked to bactericidal activity or proteolytic stability of the mature peptide....

  10. Antibacterial Efficacy of Lytic Bacteriophages against Antibiotic-Resistant Klebsiella Species

    Directory of Open Access Journals (Sweden)

    M. Khajeh Karamoddini

    2011-01-01

    Full Text Available Bacterial resistance to antibiotics is a leading and highly prevalent problem in the treatment of infectious diseases. Bacteriophages (phages appear to be effective and safe alternatives for the treatment of resistant infections because of their specificity for bacterial species and lack of infectivity in eukaryotic cells. The present study aimed to isolate bacteriophages against Klebsiella spp. and evaluate their efficacy against antibiotic-resistant species. Seventy-two antibiotic-resistant Klebsiella spp. were isolated from samples of patients who referred to the Ghaem Hospital (Mashhad, Iran. Lytic bacteriophages against Klebsiella spp. were isolated from wastewater of the septic tank of the same hospital. Bactericidal activity of phages against resistant Klebsiella spp. was tested in both liquid (tube method; after 1 and 24 h of incubation and solid (double-layer agar plate method; after 24 h of incubation phases. In each method, three different concentrations of bacteriophages (low: 107 PFU/mL were used. Bacteriophages showed promising bactericidal activity at all assessed concentrations, regardless of the test method and duration of incubation. Overall, bactericidal effects were augmented at higher concentrations. In the tube method, higher activity was observed after 24 h of incubation compared to the 1-h incubation. The bactericidal effects were also higher in the tube method compared to the double-layer agar plate method after 24 h of incubation. The findings of the present study suggest that bacteriophages possess effective bactericidal activity against resistant Klebsiella spp. These bactericidal activities are influenced by phage concentration, duration of incubation, and test method.

  11. Photocatalytic and biocidal activities of novel coating systems of mesoporous and dense TiO{sub 2}-anatase containing silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Roldán, María V. [Laboratorio de Materiales Cerámicos, FCEIA-UNR, IFIR-CONICET, Pellegrini 250, Rosario S2000BTP (Argentina); Oña, Paula de [Laboratorio de Microbiología Molecular, FCByF-UNR-CONICET, Suipacha 531, Rosario S2002LRK (Argentina); Castro, Yolanda; Durán, Alicia [Instituto de Cerámica y Vidrio (CSIC), Campus de Cantoblanco, 28049, Madrid (Spain); Faccendini, Pablo; Lagier, Claudia [IQUIR-UNR-CONICET, Suipacha 531, Rosario S2002LRK (Argentina); Grau, Roberto, E-mail: robertograu@fulbrightmail.org [Laboratorio de Microbiología Molecular, FCByF-UNR-CONICET, Suipacha 531, Rosario S2002LRK (Argentina); Pellegri, Nora S., E-mail: pellegri@fceia.unr.edu.ar [Laboratorio de Materiales Cerámicos, FCEIA-UNR, IFIR-CONICET, Pellegrini 250, Rosario S2000BTP (Argentina)

    2014-10-01

    Here we describe the development of novel nanostructured coating systems with improved photocatalytic and antibacterial activities. These systems comprise a layer of SiO{sub 2} followed by a layer of mesoporous or dense TiO{sub 2}-anatase, and doping with silver nanoparticles (Ag NPs). The coatings were synthesized via a sol–gel technique by combining colloidal Ag NPs with TiO{sub 2} and SiO{sub 2} sols. The photocatalytic activity was studied through methyl orange decomposition under UV light. Results showed a great increase of photocatalytic activity by Ag NPs doping. The most active photocatalyst corresponded to the Ag–SiO{sub 2}/TiO{sub 2} mesoporous system, associated with the porosity of the coatings and with the decrease of e–h recombination for the presence of Ag NPs. All the TiO{sub 2} coatings showed a strong bactericidal activity against planktonic forms of Gram-negative (enterohemorrhagic Escherichia coli) and Gram-positive (Listeria monocytogenes) pathogens, as well as a strong germicidal effect against deadly spores of human gas gangrene- and anthrax-producing bacteria (Clostridium perfringens and Bacillus anthracis, respectively). The bactericidal and sporocidal activity was improved by doping the coatings with Ag NPs, even more when nanoparticles were in the outer layer of TiO{sub 2}, because they are more accessible to the environment. The mechanisms responsible for the increase of photocatalytic and bactericidal behaviors related to Ag NP doping were studied by spectroscopic ellipsometry, UV–vis spectroscopy, photoluminescence and anodic stripping voltammetry. It was found that the separation of the electron–hole pair contributed to the enhancement of photocatalysis, whereas the effect of the local electric field reinforcement was probably present. A possible involvement of a decrease of band-gap energy and dispersion by silver nanoparticles is ruled out. bactericidal efficacy was increased by Ag{sup +} ion release. Overall, the results

  12. CHARACTERISTIC OF SENSITIVITY OF STAPHYLOCOCCUS AUREUS AND CANDIDA ALBICANS TO ANTIBACTERIAL PREPARATIONS AND COLLOIDAL SILVER

    Directory of Open Access Journals (Sweden)

    I. A. Afonina

    2011-01-01

    Full Text Available Abstract. Constant use of antibiotics leads to reliable increasing of resistance among microorganisms. Using non-toxic concentrations of colloidal silver in combination with antimicrobial agents can reduce using concentrations of antibiotics, kept necessary antimicrobial effect. In case of Staphylococcus aureus bactericidal activity of the complex of colloidal silver with unit concentration of neomycin is bigger than the bactericidal effect of double concentration of the antibiotic. Fungicidal effect of combination of antifungal agents with a solution of the colloidal silver on Candida albicans is equal to fungicidal effect of double concentration of antifungal drugs.

  13. Production of stable isotope enriched antimicrobial peptides in Escherichia coli: An application to the production of a 15N-enriched fragment of lactoferrin

    International Nuclear Information System (INIS)

    A method is described for the production of recombinant isotopically enriched peptides in E. coli. Peptides are produced in high yield as fusion proteins with ketosteroid isomerase which form insoluble inclusion bodies. This insoluble form allows easy purification, stabilizes the peptide against degradation and prevents bactericidal activity of the peptide. Cyanogen bromide cleavage released peptide which was conjugated with alkylamines to form lipopeptide. An important advantage of this system is that it allows production of peptides that are toxic to bacteria, which we have demonstrated on a dodecapeptide based on residues 21-31 of human bactericidal protein lactoferrin

  14. Preventive biocenosis of oil strata and combatting microbiological corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Asfandiyarov, F.A.; Kildibekov, I.G.; Nizamov, K.R.

    1984-01-01

    The following conclusions are drawn on the basis of the conducted studies: the use of chemical reagents (bactericides or bacterial corrosion inhibitors) is a rational way to combat sulfate reduction in oil strata and microbiological corrosion; the use of bactericides in the early stage of development is an effective method for sterilizing the pumped water to prevent contamination of the productive strata with sulfate reducing bacteria (SVB) and microbiological corrosion and the use of bacterial corrosion inhibitors is an effective method for suppressing microbiological corrosion and reducing sulfate reduction in the later stage of development.

  15. Moxifloxacin in the Therapy of Experimental Pneumococcal Meningitis

    OpenAIRE

    Schmidt, H.; Dalhoff, A.; Stuertz, K; Trostdorf, F.; Chen, V.; Schneider, O.; Kohlsdorfer, C.; BRÜCK, W.; Nau, R.

    1998-01-01

    The activity of moxifloxacin (BAY 12-8039) against a Streptococcus pneumoniae type 3 strain (MIC and minimum bactericidal concentration [MBC] of moxifloxacin, 0.06 and 0.25 μg/ml, respectively; MIC and MBC of ceftriaxone, 0.03 and 0.06 μg/ml, respectively) was determined in vitro and in a rabbit model of meningitis. Despite comparable bactericidal activity, 10 μg of moxifloxacin per ml released lipoteichoic and teichoic acids less rapidly than 10 μg of ceftriaxone per ml in vitro. Against exp...

  16. Mutagenesis and reparation processes in the methylotrophic bacterium Pseudomonas methanolica after UV irradiation

    International Nuclear Information System (INIS)

    High resistance of cells of methylotrophic bacterium Pseudomonas methanolica to bactericidal and mutagenous effects of ultraviolet irradiation is shown as well as activity of reparation processes after UV irradiation. The presence of low photoreactivating activity in P. methanolica is shown as well. Observed recovery in innutritious medium and decrease of irradiated cells survival rates under effect of reparation inhibitors (coffeine and acriflavine) testify to activity of excision reparation and, perhaps, recombination branch of postreplicative reparation. No manifestation of inducible reparation system is discovered. It is concluded that increased resistance of P. methanolica cells to bactericidal and mutagenous effects of short-wave ultraviolet radiation is related to activity of exact reparation systems

  17. Toxicity of laser irradiated photoactive fluoride PrF3 nanoparticles toward bacteria

    International Nuclear Information System (INIS)

    The article is devoted to exploration of biological effects of crystalline PrF3 nanoparticles toward Salmonella typhimurium TA 98 bacteria under the laser irradiation. Obtained results show bactericidal activity of PrF3 nanoparticles and optimal parameters of laser irradiation (power of laser irradiation, wavelength, diameter of the laser spoil, and exposure time) have been found under which the effects of bactericidal activity become the most significant. Survival of bacterial cells under laser irradiation with wavelength 532 nm in colloidal solution of PrF3 nanoparticles was 39%, 34%, 20% for exposure times 5 minutes, 15 minutes and 30 minutes, correspondingly

  18. Photocatalytic and biocidal activities of novel coating systems of mesoporous and dense TiO2-anatase containing silver nanoparticles

    International Nuclear Information System (INIS)

    Here we describe the development of novel nanostructured coating systems with improved photocatalytic and antibacterial activities. These systems comprise a layer of SiO2 followed by a layer of mesoporous or dense TiO2-anatase, and doping with silver nanoparticles (Ag NPs). The coatings were synthesized via a sol–gel technique by combining colloidal Ag NPs with TiO2 and SiO2 sols. The photocatalytic activity was studied through methyl orange decomposition under UV light. Results showed a great increase of photocatalytic activity by Ag NPs doping. The most active photocatalyst corresponded to the Ag–SiO2/TiO2 mesoporous system, associated with the porosity of the coatings and with the decrease of e–h recombination for the presence of Ag NPs. All the TiO2 coatings showed a strong bactericidal activity against planktonic forms of Gram-negative (enterohemorrhagic Escherichia coli) and Gram-positive (Listeria monocytogenes) pathogens, as well as a strong germicidal effect against deadly spores of human gas gangrene- and anthrax-producing bacteria (Clostridium perfringens and Bacillus anthracis, respectively). The bactericidal and sporocidal activity was improved by doping the coatings with Ag NPs, even more when nanoparticles were in the outer layer of TiO2, because they are more accessible to the environment. The mechanisms responsible for the increase of photocatalytic and bactericidal behaviors related to Ag NP doping were studied by spectroscopic ellipsometry, UV–vis spectroscopy, photoluminescence and anodic stripping voltammetry. It was found that the separation of the electron–hole pair contributed to the enhancement of photocatalysis, whereas the effect of the local electric field reinforcement was probably present. A possible involvement of a decrease of band-gap energy and dispersion by silver nanoparticles is ruled out. bactericidal efficacy was increased by Ag+ ion release. Overall, the results included in this article show that the architecture of

  19. Lethality of a Heat- and Phosphate-Catalyzed Glucose By-Product to Escherichia coli O157:H7 and Partial Protection Conferred by the rpoS Regulon

    OpenAIRE

    Byrd, Jeffrey J.; Cheville, Ann M.; Bose, Jeffrey L.; Kaspar, Charles W.

    1999-01-01

    A by-product of glucose produced during sterilization (121°C, 15 lb/in2, 15 min) at neutral pH and in the presence of phosphate (i.e., phosphate-buffered saline) was bactericidal to Escherichia coli O157:H7 (ATCC 43895). Other six-carbon (fructose and galactose) and five-carbon (arabinose, ribose, and xylose) reducing sugars also produced a toxic by-product under the same conditions. Fructose and the five-carbon sugars yielded the most bactericidal activity. Glucose concentrations of 1% (wt/v...

  20. Potent Antibacterial Antisense Peptide-Peptide Nucleic Acid Conjugates Against Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Ghosal, Anubrata; Nielsen, Peter E

    2012-01-01

    inhibition of P. aeruginosa strains PA01, PA14, and LESB58 at 1-2¿µM concentrations without any indication of bacterial membrane disruption (even at 20¿µM), and resulted in specific reduction of the targeted mRNA levels. One of the four compounds showed clear bactericidal activity while the other...

  1. Genetics of Serum Resistance in Neisseria gonorrhoeae: The sac-1 Genetic Locus

    OpenAIRE

    Cannon, Janne G.; Lee, Terrence J.; Guymon, Lawrence F.; Sparling, P. Frederick

    1981-01-01

    A genetic locus affecting susceptibility to the bactericidal activity of normal human serum has been designated sac-1. This locus was shown to be closely linked to, but not identical with, a second locus (designated nmp-2) that affects protein 1 of the outer membrane. The sac-1 locus could be linked to known antibiotic resistance markers on the gonococcal chromosome by genetic transformation.

  2. Drug: D05448 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D05448 Drug Pexiganan acetate (USAN); Cytolex (TN) C122H210N32O22. (C2H4O2)x Gly Ile Gly Lys Phe ... Ile Leu Lys Lys-NH2 Peptide Treatment of diabetic foot ... ulcer infections [antibacterial] bactericidal perm ...

  3. Antibacterial action of doped CoFe2O4 nanocrystals on multidrug resistant bacterial strains

    International Nuclear Information System (INIS)

    The bactericidal effect of pristine and doped cobalt ferrite nanoparticles has been evaluated against multiple drug resistant clinical strains by assessing the number of colony-forming units (CFU). Monophasic polycrystalline ferrites have been prepared by the malate–glycolate sol–gel autocombustion method as confirmed by the X-ray diffraction study. Various changes occurring during the preparative stages have been demonstrated using TG–DTA analysis which is well complemented by the FTIR spectroscopy. The antibacterial studies carried out demonstrate a bactericidal effect of the nanoparticles wherein the number of CFU has been found to decrease with doping. Cellular distortions have been revealed through SEM. Variation in the number of CFU with dopant type has also been reported herein. - Graphical abstract: Antibacterial action of doped cobalt ferrites resulting in the lyses of multi-drug resistant bacterial strains. - Highlights: • The paper reports an antibacterial study of rare earth doped cobalt ferrite nanoparticles. • Monophasic compounds have been prepared by the sol–gel autocombustion method. • Bactericidal property has been evaluated based on the number of colony forming units. • Variation in bactericidal action with respect to the dopant type has been observed. • Cellular distortions resulting in cell lysis are confirmed from the SEM images

  4. Antimicrobial Susceptibility of Escherichia coli Strains Isolated from Alouatta spp. Feces to Essential Oils

    OpenAIRE

    Valéria Maria Lara; Adriano Bonfim Carregaro; Deise Flores Santurio; Mariangela Facco de Sá; Janio Moraes Santurio; Sydney Hartz Alves

    2016-01-01

    This study evaluated the in vitro antibacterial activity of essential oils from Lippia graveolens (Mexican oregano), Origanum vulgaris (oregano), Thymus vulgaris (thyme), Rosmarinus officinalis (rosemary), Cymbopogon nardus (citronella), Cymbopogon citratus (lemongrass), and Eucalyptus citriodora (eucalyptus) against Escherichia coli (n = 22) strains isolated from Alouatta spp. feces. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined for each ...

  5. Polyelectrolytes with high charge density

    Science.gov (United States)

    Rembaum, A.; Yen, S. P. S.

    1974-01-01

    Polymers can be used as flocculants to clarify residential and industrial water supplies and as bactericidal and fungicidal agents. They can be used in preparation of electroconductive photocopy papers, to improve living cell adhesion to glass or plastic, and as anticancer agents.

  6. Identification of New Sources of Resistance to Xanthomonas translucens pv. undulosa in Winter Wheat

    Science.gov (United States)

    : Bacterial leaf streak (BLS) caused by Xanthomonas translucens pv. undulosa, has emerged as an important disease of wheat in the United States. Planting resistant varieties offers the best strategy to manage BLS in the absence of effective bactericides. However, most of the wheat varieties current...

  7. Synergistic effects between amoxicillin, metronidazole, and the hydroxymetabolite of metronidazole against Actinobacillus actinomycetemcomitans.

    OpenAIRE

    Pavicić, M J; van Winkelhoff, A J; de Graaff, J

    1991-01-01

    Interactions between metronidazole and amoxicillin, metronidazole and its hydroxymetabolite, and amoxicillin and the hydroxymetabolite of metronidazole were investigated with checkerboard titrations in combination with accurately determined MICs and MBCs. Actinobacillus actinomycetemcomitans was used as the test organism. Synergism was found for all three combinations. Fractional inhibitory concentration indices and fractional bactericidal concentration indices varied from 0.3 to 0.7. These s...

  8. SRI-286, a Thiosemicarbazole, in Combination with Mefloquine and Moxifloxacin for Treatment of Murine Mycobacterium avium Complex Disease

    OpenAIRE

    Bermudez, Luiz E.; Kolonoski, Peter; Seitz, Lianne E.; Petrofsky, Mary; Reynolds, Robert; Wu, Martin; Young, Lowell S.

    2004-01-01

    Treatment of Mycobacterium avium disease remains challenging when macrolide resistance develops. We infected C57 beige mice and treated them with mefloquine, SRI-286, and moxifloxacin. SRI-286 (80 mg/kg) was bactericidal in the liver. Mefloquine plus moxifloxacin or mefloquine plus SRI-286 were better than mefloquine alone.

  9. Bioefficacy of Lantana camara L. against some human pathogens

    Directory of Open Access Journals (Sweden)

    Sharma B

    2009-01-01

    Full Text Available Antimicrobial efficacy of flavonoids (free and bound and crude alkaloids of Lantana camara L. was determined by disc diffusion assay against three bacteria (Escherichia coli, Proteus mirabilis, and Staphylococcus aureus and two fungi (Candida albicans and Trichophyton mentagrophytes. Minimum inhibitory concentration, minimum bactericidal/fungicidal concentration and total activity were also studied. Most susceptible microorganism in the present study was C. albicans followed by P. mirabilis, S. aureus, E. coli, and T. mentagrophytes. The range of minimum inhibitory concentration of tested extracts was 0.039-0.625 mg/ml while minimum bactericidal/fungicidal concentration ranged from 0.078-1.25 mg/ml. Six extracts out of eleven tested showed same values of minimum inhibitory concentration and minimum bactericidal/fungicidal concentration, while rest showed higher values of minimum bactericidal/fungicidal concentration. Highest total activity (120.51 ml/g was observed for bound flavonoids of root against Candida albicans and Staphylococcus aureus. Results of the present investigation indicate that Lantana camara has good antimicrobial activity with low range of minimum inhibitory concentration hence can be exploited for future plant based antimicrobial drugs.

  10. Fate of Triclosan in activated sludge treatment - bridging the missing gap

    DEFF Research Database (Denmark)

    Bester, Kai; Chen, Xijuan; Furgal, Karolina;

    Triclosan is a bactericide used in increasing shelflife of cosmetics, improving hygenics in sportswear as well as in toothpaste and in mouth wash. More than 350 tons Triclosan is annually produced in Europe, and most of it finally is emitted into wastewater at the end of its life cycle. Therefore...

  11. Tuberculous Pericarditis is Multibacillary and Bacterial Burden Drives High Mortality

    Directory of Open Access Journals (Sweden)

    Jotam G. Pasipanodya

    2015-11-01

    Interpretation: Patients with culture confirmed tuberculous pericarditis have a high bacillary burden, and this bacterial burden drives mortality. Thus proven tuberculosis pericarditis is not a paucibacillary disease. Moreover, the severe immunosuppression suggests limited inflammation. There is a need for the design of a highly bactericidal regimen for this condition.

  12. Lysostaphin in treatment of neonatal Staphylococcus aureus infection.

    Science.gov (United States)

    Oluola, Okunola; Kong, Lingkun; Fein, Mindy; Weisman, Leonard E

    2007-06-01

    This study describes lysostaphin's effect against methicillin-sensitive Staphylococcus aureus in suckling rats. Standard techniques determined minimal inhibitory and bactericidal concentrations, pharmacokinetics, and efficacy. The numbers of surviving rats after vancomycin, oxacillin, and lysostaphin treatment were comparable and were different from that of controls (P < 0.00001). Lysostaphin appears effective in the treatment of neonatal S. aureus infection. PMID:17420212

  13. Surface tension of compositions of polyhexametyleneguanidine hydrochloride - surfactants

    Directory of Open Access Journals (Sweden)

    S. Kumargaliyeva

    2012-12-01

    Full Text Available We made up songs bactericidal polyhexamethyleneguanidine hydrochloride (metacyde with the surface-active substances - anionic sodium dodecylsulfate, cationic cetylpyridinium bromide, and nonionic Tween-80 and measured the surface tension of water solutions. The study showed that the composition metacyde with surface-active agents have a greater surface activity than the individual components.

  14. Activity of sparfloxacin on Staphylococcus epidermidis attached to plastic catheters.

    Science.gov (United States)

    Pascual, A; García, I; Ramirez de Arellano, E; Perea, E J

    1995-08-01

    The activity of sparfloxacin on Staphylococcus epidermidis biofilms on different plastic catheters was evaluated. Sparfloxacin showed high bactericidal activity against S. epidermidis biofilms on Vialon and polyvinylchloride catheters. The combination of sparfloxacin with amikacin or rifampicin significantly increased its activity against bacterial biofilms on polyurethane and Teflon catheters. PMID:8522473

  15. Antipneumococcal Activity of Dalbavancin Compared to Other Agents

    OpenAIRE

    Lin, Gengrong; Smith, Kathy; Ednie, Lois M.; Appelbaum, Peter C.

    2005-01-01

    Against 307 pneumococci of various resistotypes, dalbavancin MICs were 0.008 to 0.125 μg/ml. All strains were susceptible to vancomycin, teicoplanin, linezolid, and quinupristin-dalfopristin. Dalbavancin at 2× MIC was bactericidal against all 10 pneumococci tested after 24 h. Vancomycin and teicoplanin killed 10 and 8 strains, respectively, at 2× MIC after 24 h.

  16. Safe, Effective Use of Pesticides, A Manual for Commercial Applicators: Fruit Pest Control.

    Science.gov (United States)

    Brunner, J.; And Others

    This manual is intended to assist pesticide applicators prepare for certification under the Michigan Pesticide Control Act of 1976. The primary focus of this publication is on fruit pest control. Sections included are: (1) Causes of fruit diseases; (2) Fruit fungicides and bactericides; (3) Insect and mite pests; (4) Insecticides and miticides;…

  17. Antimicrobial properties of N-carboxybutyl chitosan.

    OpenAIRE

    Muzzarelli, R; Tarsi, R; Filippini, O; Giovanetti, E; G. Biagini; Varaldo, P E

    1990-01-01

    N-Carboxybutyl chitosan, a modified chitin of crustacean origin, displayed inhibitory, bactericidal, and candidacidal activities when tested against 298 cultures of various pathogens. Examination by electron microscopy showed that microbial cells exposed to N-carboxybutyl chitosan underwent marked morphological alterations. The data are of importance in defining the suitability of N-carboxybutyl chitosan as a wound dressing.

  18. In Vitro Susceptibility Testing of Four Antibiotics against Borrelia burgdorferi: a Comparison of Results for the Three Genospecies Borrelia afzelii, Borrelia garinii, and Borrelia burgdorferi Sensu Stricto

    OpenAIRE

    Sicklinger, Martin; Wienecke, Ralf; Neubert, Uwe

    2003-01-01

    MICs and minimal bactericidal concentrations (MBCs) were evaluated for the four antibiotics azithromycin, amoxicillin, ceftriaxone, and doxycycline against the three main genospecies of Borrelia burgdorferi sensu lato. In MBC testing, statistically significant differences between the genospecies could be found in 7 out of 12 comparative evaluations (P < 0.05).

  19. In-vitro-Sensibilität von Borrelia burgdorferi sensu lato gegenüber vier Antibiotika: ein Vergleich der Genospezies Borrelia afzelii, Borrelia garinii und Borrelia burgdorferi sensu stricto

    OpenAIRE

    Sicklinger, Martin

    2006-01-01

    MICs and minimal bactericidal concentrations (MBCs) were evaluated for the four antibiotics azithromycin, amoxicillin, ceftriaxone, and doxycycline against the three main genospecies of Borrelia burgdorferi sensu lato. In MBC testing, statistically significant differences between the genospecies could be found in 7 out of 12 comparative evaluations (P < 0.05).

  20. An antibacterial assay of aqueous extract of garlic against anaerobic/microaerophilic and aerobic bacteria

    OpenAIRE

    Elsom, Giles K.; Hide, Denis; Salmon, David M.

    2011-01-01

    Both the minimum inhibitory and minimum bactericidal concentration (expressed in terms of thiosulphinate concentration) of an aqueous extract of garlic was determined against nine species of bacteria. Helicobacter pylori proved to be extremely sensitive to garlic extract, whilst Bacteroides fragilis, Clostridium perfringens, Enterobacter cloacae, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium and Staphylococcus aureus all were moderately sensitive to the garlic extract treat...

  1. In Vitro Susceptibilities of Seven Leptospira Species to Traditional and Newer Antibiotics

    OpenAIRE

    Hospenthal, Duane R.; Murray, Clinton K.

    2003-01-01

    Human leptospirosis is generally treated with penicillin or doxycycline. We studied the susceptibilities of 11 serovars (seven species) of Leptospira to 14 antibiotics. With the exception of chloramphenicol, all tested agents were at least as potent as penicillin and doxycycline, with the macrolide and ketolide drugs producing the lowest MICs (and minimal bactericidal concentrations).

  2. Organic Matter Application Can Reduce Copper Toxicity in Tomato Plants

    Science.gov (United States)

    Campbell, Brian

    2010-01-01

    Copper fungicides and bactericides are often used in tomato cultivation and can cause toxic Cu levels in soils. In order to combat this, organic matter can be applied to induce chelation reactions and form a soluble complex by which much of the Cu can leach out of the soil profile or be taken up safely by plants. Organic acids such as citric,…

  3. Antimycobacterial activity of bacteriocins and their complexes with liposomes

    Science.gov (United States)

    Bacteriocins (Bcn) are natural peptides that are secreted by taxonomically distinct bacteria which exert bactericidal activity against other bacterial species. Their capacity to inhibit growth of virulent Mycobacterium tuberculosis H37Rv was evaluated in this study. Five Bcn were purified from sel...

  4. Eugenol alters the integrity of cell membrane and acts against the nosocomial pathogen Proteus mirabilis.

    Science.gov (United States)

    Devi, K Pandima; Sakthivel, R; Nisha, S Arif; Suganthy, N; Pandian, S Karutha

    2013-03-01

    Eugenol, a member of the phenylpropanoids class of chemical compounds, is a clear to pale yellow oily liquid extracted from certain essential oils especially from clove oil, nutmeg, cinnamon, and bay leaf. The antibacterial activity of eugenol and its mechanism of bactericidal action against Proteus mirabilis were evaluated. Treatment with eugenol at their minimum inhibitory concentration [0.125 % (v/v)] and minimum bactericidal concentration [0.25 % (v/v)] reduced the viability and resulted in complete inhibition of P. mirabilis. A strong bactericidal effect on P. mirabilis was also evident, as eugenol inactivated the bacterial population within 30 min exposure. Chemo-attractant property and the observance of highest antibacterial activity at alkaline pH suggest that eugenol can work more effectively when given in vivo. Eugenol inhibits the virulence factors produced by P. mirabilis as observed by swimming motility, swarming behavior and urease activity. It interacts with cellular membrane of P. mirabilis and makes it highly permeable, forming nonspecific pores on plasma membrane, which in turn directs the release of 260 nm absorbing materials and uptake of more crystal violet from the medium into the cells. SDS-polyacrylamide gel, scanning electron microscopy and Fourier transform infrared analysis further proves the disruptive action of eugenol on the plasma membrane of P. mirabilis. The findings reveal that eugenol shows an excellent bactericidal activity against P. mirabilis by altering the integrity of cell membrane. PMID:23444040

  5. In vitro activities of temafloxacin (A-62254) and four other antibiotics against Chlamydia trachomatis.

    OpenAIRE

    Segreti, J; Kessler, H A; Kapell, K S; Trenholme, G M

    1989-01-01

    The in vitro activity of temafloxacin (A-62254), a new quinolone antibiotic, against 13 strains of Chlamydia trachomatis was determined and compared with those of doxycycline, norfloxacin, ciprofloxacin, and difloxacin. Temafloxacin and difloxacin were the most active quinolones tested, with bactericidal activity comparable to that of doxycycline.

  6. Determination of antibacterial activity of green coffee bean extract on periodontogenic bacteria like Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans: An in vitrostudy

    OpenAIRE

    Nagaraj Bharath; Nagur Karibasappa Sowmya; Dhoom Singh Mehta

    2015-01-01

    Background: The aim of this study was to evaluate the antibacterial activity of pure green coffee bean extract on periodonto pathogenic bacteria Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn) and Aggregatibacter actinomycetemcomitans (Aa). Materials and Methods: Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBC) were used to assess the antibacterial effect of pure green coffee bean extract against periodonto pathogen...

  7. Antibacterial efficiency of silver-doped layers of titanium alloy Ti6Al4V and 316L steel

    Czech Academy of Sciences Publication Activity Database

    Kocourek, Tomáš; Jelínek, Miroslav; Mikšovský, Jan; Vymětalová, V.; Zezulová, Markéta; Jurek, Karel

    Strasbourg: European Materials Research Society, 2012 - (Dusastre, V.) [E- MRS 2012 Spring Meeting. 14.05.2012-18.05.2012, Strasbourg] Institutional research plan: CEZ:AV0Z10100522 Keywords : bactericidal * steel * silver * Ti6Al4V * PLD Subject RIV: BM - Solid Matter Physics ; Magnetism

  8. Expression profiles of seven channel catfish antimicrobial peptides in response to Edwardsiella ictaluri infection

    Science.gov (United States)

    Using quantitative PCR technique, the relative transcriptional levels of seven channel catfish antimicrobial peptide (AMP) genes [NK-lysin type 1, NK-lysin type 2, NK-lysin type 3, bactericidal permeability-increasing protein (BPI), cathepsin D, hepcidin, and liver-expressed antimicrobial peptide 2 ...

  9. Optimizing the distance for bacterial treatment using surface micro-discharge plasma

    International Nuclear Information System (INIS)

    Reactive plasma species generated by a surface micro-discharge (SMD) electrode are delivered to the target by diffusion and/or convection. In humid air conditions, the diffusion process is coupled with complicated plasma chemical reactions, which affect the density profiles of bactericidal agents. One may expect that the production of reactive plasma species can be optimized at a certain distance. Our experimental results found the optimum distance for achieving the highest bactericidal efficiency with plasma treatment using an SMD electrode. The optimum distance is about 2-4 mm from the SMD electrode to the target and depends on the geometry of the experiment. The bactericidal efficiency in the plasma-treated area can be improved by a factor of 30 if the bacterial samples are placed at the optimum distance. The results show the predominant role of the long-lived reactive plasma species. It is seen that the diffusion model of multi-plasma species with coupled plasma chemical reactions would be highly important for understanding the bactericidal property of cold atmospheric plasmas and therefore for optimizing cold atmospheric plasma sources for medical and biological applications. (paper)

  10. The new additive to improve the stability of hydrocarbon fuels

    Directory of Open Access Journals (Sweden)

    В.О. Чугуй

    2009-02-01

    Full Text Available  The antimicrobial PGMG is offered as biocyde additive for defence of aviation fuels from microbial contamination. The bactericidal concentrations of PGMG are set up for some bacteria separate from a contamination fuel. Influencing of bringing of different concentrations of PGMG in different solvents on the high-quality indexes of fuel is studied.

  11. CFD Simulation of the distribution of ClO2 in fresh produce to improve safety

    Science.gov (United States)

    The shelf life of fresh-cut produce may be prolonged with the injection of bactericide gases like chlorine dioxide (ClO2). A comparative study has been conducted by modeling the injection of three different gases, CO2, ClO2 and N2 inside a PET clamshell containers commonly use to package fresh produ...

  12. Antagonism between penicillin and erythromycin against Streptococcus pneumoniae in vitro and in vivo

    DEFF Research Database (Denmark)

    Johansen, H K; Jensen, T G; Dessau, Ram;

    2000-01-01

    effect of the bactericidal agent. In this study, the possible interaction between penicillin and erythromycin was investigated in vitro and in vivo against four clinical isolates of Streptococcus pneumoniae with MICs of penicillin ranging from 0.016 to 0.5 mg/L and of erythromycin from 0. 25 to >128 mg...

  13. Degradation of Triclosan in aerated sludge

    DEFF Research Database (Denmark)

    Bester, Kai; Chen, Xijuan; Furgal, Karolina;

    Triclosan is a bactericide used in increasing shelflife of cosmetics, improving hygenics in sportswear as well as in toothpaste and in mouth wash. More than 350 tons Triclosan is annually produced in Europe, and most of it finally is emitted into wastewater at the end of its life cycle. Therefore...

  14. Towards the understanding of non-thermal airplasma action: effects on bacteria and fibroblasts

    Czech Academy of Sciences Publication Activity Database

    Lunov, Oleg; Zablotskyy, Vitaliy A.; Churpita, Olexandr; Jäger, Aleš; Polívka, Leoš; Syková, Eva; Terebova, N.; Kulikov, A.; Kubinová, Šárka; Dejneka, Alexandr

    2016-01-01

    Roč. 6, č. 30 (2016), 25286-25292. ISSN 2046-2069 R&D Projects: GA MŠk(CZ) LM2011026; GA MŠk(CZ) LO1309 Institutional support: RVO:68378271 ; RVO:68378041 Keywords : non-thermal plasma * bactericidal effects * medical applications Subject RIV: BO - Biophysics Impact factor: 3.840, year: 2014

  15. Antibacterial activities of magnesium oxide (MgO) nanoparticles against foodborne pathogens

    Science.gov (United States)

    The antibacterial activities of magnesium oxide nanoparticles (MgO NP) alone or in combination with other antimicrobials (nisin and ZnO NP) against E. coli O157:H7 and Salmonella Stanley were investigated. The results show that MgO NP have strong bactericidal activity against the pathogens, achievin...

  16. Gene : CBRC-RMAC-12-0024 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available n receptor, YWTD repeat [Chloroflexus aggregans DSM 9485] 2.9 30% gnl|UG|Mmu#S33379730 PREDICTED: Macaca mulatta bactericidal/permeab...ility-increasing protein (BPI), partial mRNA /cds=p(1,18

  17. Tandem shock waves in medicine and biology: a review of potential applications and successes

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Fernández, F.; Gutiérrez-Aceves, J.; Fernández, E.; Alvarez, U.M.; Šunka, Pavel; Loske, A.M.

    2016-01-01

    Roč. 26, č. 1 (2016), s. 1-23. ISSN 0938-1287 Institutional support: RVO:61389021 Keywords : Tandem shock waves * Acoustic cavitation * Clinical applications * Bactericidal effect * Genetic transformation * Cancer treatment Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.885, year: 2014 http://link.springer.com/article/10.1007%2Fs00193-015-0577-0

  18. Effects of arsenic trioxide inhalation exposure on pulmonary antibacterial defenses in mice

    International Nuclear Information System (INIS)

    The effects of single and multiple (5 and 20) 3-h inhalation exposures to aerosols of arsenic trioxide on the pulmonary defense system of mice were investigated. Arsenic trioxide mist was generated from an aqueous solution and dried to produce particulate aerosols of 0. 4 micron mass median aerodynamic diameter. Aerosol mass concentration ranged from 125 to 1000 micrograms As/m3. Effects of the exposures were evaluated by determination of changes in susceptibility to experimentally induced streptococcal aerosol infection and in pulmonary bactericidal activity to 35S-labeled Klebsiella pneumoniae. Significant increases in mortality due to the infectious challenge and decreases in bactericidal activity were seen after single 3-h exposures to 270, 500, and 940 micrograms As/m3. Similarly, 5 or 20 multiple 3-h exposures to 500 micrograms As/m3 produced consistently significant increases in mortality and decreases in pulmonary bactericidal activity. At 125 or 250 micrograms As/m3, a decrease in bactericidal activity was seen only after 20 exposures to 250 micrograms/m3. Results from earlier studies with an arsenic-containing copper smelter dust were compared to these data. The possibility of the development of adaptation during multiple exposures to arsenic trioxide is also considered

  19. Effectiveness of Meningococcal B Vaccine against Endemic Hypervirulent Neisseria meningitidis W Strain, England.

    Science.gov (United States)

    Ladhani, Shamez N; Giuliani, Marzia Monica; Biolchi, Alessia; Pizza, Mariagrazia; Beebeejaun, Kazim; Lucidarme, Jay; Findlow, Jamie; Ramsay, Mary E; Borrow, Ray

    2016-02-01

    Serum samples from children immunized with a meningococcal serogroup B vaccine demonstrated potent serum bactericidal antibody activity against the hypervirulent Neisseria meningitidis serogroup W strain circulating in England. The recent introduction of this vaccine into the United Kingdom national immunization program should also help protect infants against this endemic strain. PMID:26811872

  20. Antibacterial action of doped CoFe{sub 2}O{sub 4} nanocrystals on multidrug resistant bacterial strains

    Energy Technology Data Exchange (ETDEWEB)

    Velho-Pereira, S.; Noronha, A.; Mathias, A.; Zakane, R.; Naik, V.; Naik, P. [Department of Biotechnology, St. Xavier' s College, Goa (India); Salker, A.V. [Department of Chemistry, Goa University, Goa (India); Naik, S.R., E-mail: srnaik19@gmail.com [Department of Chemistry, St. Xavier' s College, Goa (India)

    2015-07-01

    The bactericidal effect of pristine and doped cobalt ferrite nanoparticles has been evaluated against multiple drug resistant clinical strains by assessing the number of colony-forming units (CFU). Monophasic polycrystalline ferrites have been prepared by the malate–glycolate sol–gel autocombustion method as confirmed by the X-ray diffraction study. Various changes occurring during the preparative stages have been demonstrated using TG–DTA analysis which is well complemented by the FTIR spectroscopy. The antibacterial studies carried out demonstrate a bactericidal effect of the nanoparticles wherein the number of CFU has been found to decrease with doping. Cellular distortions have been revealed through SEM. Variation in the number of CFU with dopant type has also been reported herein. - Graphical abstract: Antibacterial action of doped cobalt ferrites resulting in the lyses of multi-drug resistant bacterial strains. - Highlights: • The paper reports an antibacterial study of rare earth doped cobalt ferrite nanoparticles. • Monophasic compounds have been prepared by the sol–gel autocombustion method. • Bactericidal property has been evaluated based on the number of colony forming units. • Variation in bactericidal action with respect to the dopant type has been observed. • Cellular distortions resulting in cell lysis are confirmed from the SEM images.

  1. Identification of copper-induced genes in Pseudomonas fluorescens and use of a reporter strain to monitor bioavailable copper in soil

    DEFF Research Database (Denmark)

    Tom-Petersen, Andreas; Hosbond, Carsten; Nybroe, Ole

    2001-01-01

    Copper (Cu) is an essential trace metal required by living organisms but it is potentially toxic at higher concentrations. Cu salts are used as bactericides in agriculture and as growth promoters in pig production. They are consequently introduced to the environment, e.g. through manure, and migh...

  2. Colloidal metal oxide nanoparticle systems: the new promising way to prevent antibiotic resistance during treatment of local infectious processes

    Science.gov (United States)

    Karasenkov, Y.; Frolov, G.; Pogorelsky, I.; Latuta, N.; Gusev, A.; Kuznetsov, D.; Leont'ev, V.

    2015-11-01

    New bactericidal containing nanoparticles colloids for application in dentistry, maxillofacial surgery, urology, obstetrics, gynaecology, ENT, proctology have been developed. The various water colloidal nanodispersive systems of metals and oxides have been obtained by means of electric impulse - condensation (electroerosion) method. These systems are based pure elements and alloys of argentum (Ag), titanium dioxide (TiO2), iron oxide (Fe2O3), tantalum oxide (TaO), vanadium oxide (VO2), cobalt oxide (CoO), tantalum dioxide TaO2, zinc oxide (ZnO), copper oxide (CuO) and mixed suspensions of titanium, aluminium and molybdenum oxides. The research has been made on culture of dentobacterial plaque and mixed culture issued from gingival spaces. The composition of culture was identified with S.aureus, S.epidermidis and nonfermentable kinds of E.coli. The observation period lasted more than nineteen days. All solutions showed highly prolonged bactericidal activity in dilutions from the whole solution 1-20 mg/L. The bactericidal activity of powder specimen of silica containing Ag and Fe2O3 nanoparticles used as dental filling material and disintegrates of composite materials (produced by “StomaDent” CJSC) have been studied. Tested materials have long (up to 19 days and more) bactericidal activity.

  3. The involvement of donor specific CTL in cardiac transplant rejection: relevance of avidity

    NARCIS (Netherlands)

    N.E.M. van Emmerik (Nancy)

    1998-01-01

    textabstractWhen a micro-organism penetrates the body, defensive mechanisms of the non-specific innate immune system come into play, such as soluble chemical factors (bactericidal lysozyme, acute phase proteins, interferons), extracellular killing (NK cells, eosinophils), and phagocytosis (macrophag

  4. Taking Out TB–Lysosomal Trafficking and Mycobactericidal Ubiquitin-Derived Peptides

    OpenAIRE

    Purdy, Georgiana E.

    2011-01-01

    Tuberculosis remains a significant global health concern. The hallmark of Mycobacterium tuberculosis pathogenicity is its ability to infect resting macrophages and establish an intracellular niche. Activated and autophagic macrophages control mycobacterial infections through bactericidal mechanisms ranging from reactive oxygen and nitrogen intermediates to the delivery of the bacterium to the acidified, hydrolytically active lysosome. The mycobactericidal activity of the lysosome is due in pa...

  5. Taking out TB – A role for lysosomal ubiquitin-derived peptides

    OpenAIRE

    Georgiana ePurdy

    2011-01-01

    Tuberculosis remains a significant global health concern. The hallmark of Mycobacterium tuberculosis pathogenicity is its ability to infect resting macrophages and establish an intracellular niche. Activated and autophagic macrophages control mycobacterial infections through bactericidal mechanisms ranging from reactive oxygen and nitrogen intermediates to the delivery of the bacterium to the acidified, hydrolytically active lysosome. The mycobactericidal activity of the lysosome is due in pa...

  6. Transformation of serum-susceptible Escherichia coli O111 with p16Slux plasmid to allow for real-time monitoring of complement-based inactivation of bacterial growth in bovine milk.

    Science.gov (United States)

    Maye, S; Stanton, C; Fitzgerald, G F; Kelly, P M

    2016-01-01

    Complement activity has only recently been characterized in raw bovine milk. However, the activity of this component of the innate immune system was found to diminish as milk was subjected to heat or partitioning during cream separation. Detection of complement in milk relies on a bactericidal assay. This assay exploits the specific growth susceptibility of Escherichia coli O111 to the presence of complement. Practical application of the assay was demonstrated when a reduction in complement activity was recorded in the case of pasteurized and reduced-fat milks. This presented an opportunity to improve the functionality of the bactericidal assay by incorporating bioluminescence capability into the target organism. Following some adaptation, the strain was transformed by correctly integrating the p16Slux plasmid. Growth properties of the transformed strain of E. coli O111 were unaffected by the modification. The efficacy of the strain adaptation was correlated using the LINEST function analysis [r=0.966; standard error of prediction (SEy)=0.957] bioluminescence with that of bactericidal assay total plate counts within the range of 7.5 to 9.2 log cfu/mL using a combination of raw and processed milk samples. Importantly, the transformed E. coli O111 p16Slux strain could be identified in milk and broth samples using bioluminescence measurement, thus enabling the bactericidal assay-viability test to be monitored in real time throughout incubation. PMID:26585477

  7. Decreased outer membrane permeability protects mycobacteria from killing by ubiquitin-derived peptides.

    Science.gov (United States)

    Purdy, Georgiana E; Niederweis, Michael; Russell, David G

    2009-09-01

    Ubiquitin-derived peptides are bactericidal in vitro and contribute to the mycobactericidal activity of the lysosome. To further define interactions of ubiquitin-derived peptides with mycobacteria, we screened for mutants with increased resistance to the bactericidal activity of the synthetic ubiquitin-derived peptide Ub2. The four Ub2-resistant Mycobacterium smegmatis mutants were also resistant to the bactericidal action of other antimicrobial peptides and macrophages. Two mutants were in the mspA gene encoding the main M. smegmatis porin. Using a translocation-deficient MspA point mutant, we showed that susceptibility of M. smegmatis to Ub2 was independent of MspA channel activity. Instead, the M. smegmatis Ub2-resistant mutants shared a common phenotype of decreased cell wall permeability compared with wild-type bacteria. Expression of mspA rendered Mycobacterium tuberculosis CDC1551 more susceptible both to ubiquitin-derived peptides in vitro and to lysosomal killing in macrophages. Finally, biochemical assays designed to assess membrane integrity indicated that Ub2 treatment impairs membrane function of M. smegmatis and M. tuberculosis cells. The M. smegmatis Ub2-resistant mutants were more resistant than wild-type M. smegmatis to this damage. We conclude that Ub2 targets mycobacterial membranes and that reduced membrane permeability provides mycobacteria intrinsic resistance against antimicrobial compounds including bactericidal ubiquitin-derived peptides. PMID:19682257

  8. Legionella pneumophila transcriptional response following exposure to CuO nanoparticles

    Science.gov (United States)

    Copper ions are an effective antimicrobial agent used to control Legionnaires’ disease and Pontiac fever arising from institutional drinking water systems. Here we present data on an alternative bactericidal agent, CuO nanoparticles (CuO-NPs), and test its efficacy at three conce...

  9. Removal of triclocarban and triclosan in a wastewater treatment plant and their accumulations onto the solids

    Science.gov (United States)

    The objective of this study was to investigate the fate of Triclosan (5-chloro-2-[2,4-dichloro-phenoxy]-phenol (TCS) and triclocarban (N-(4-chlorophenyl)-N’-(3,4-dichlorophenyl)urea) (TCC) within a wastewater treatment plant (WWTP). TCS and TCC are bactericidal compounds that have been detected in ...

  10. Fate of triclocarban and triclosan in soils receiving biosolids applications

    Science.gov (United States)

    Triclosan (5-chloro-2-[2,4-dichloro-phenoxy]-phenol (TCS) and triclocarban (N-(4-chlorophenyl)-N’-(3,4-dichlorophenyl)urea) (TCC) are bactericidal compounds that are added to a wide range of household and personal care products such as hand soap, dish washing products, laundry detergents, cleaning w...

  11. Activity of and Resistance to Moxifloxacin in Staphylococcus aureus

    OpenAIRE

    Ince, Dilek; Zhang, Xiamei; Hooper, David C.

    2003-01-01

    Moxifloxacin has enhanced potency against Staphylococcus aureus, lower propensity to select for resistant mutants, and higher bactericidal activity against highly resistant strains than ciprofloxacin. Despite similar activity against purified S. aureus topoisomerase IV and DNA gyrase, it selects for topoisomerase IV mutants, making topoisomerase IV the preferred target in vivo.

  12. A validated spectrofluorimetric method for the determination of nifuroxazide through coumarin formation using experimental design

    OpenAIRE

    El-Zaher, Asmaa Ahmed; Mahrouse, Marianne Alphonse

    2013-01-01

    Background Nifuroxazide (NF) is an oral nitrofuran antibiotic, having a wide range of bactericidal activity against gram positive and gram negative enteropathogenic organisms. It is formulated either in single form, as intestinal antiseptic or in combination with drotaverine (DV) for the treatment of gastroenteritis accompanied with gastrointestinal spasm. Spectrofluorimetry is a convenient and sensitive technique for pharmaceutical quality control. The new proposed spectrofluorimetric method...

  13. Anticariogenic activity of some tropical medicinal plants against Streptococcus mutans.

    Science.gov (United States)

    Hwang, Jae-Kwan; Shim, Jae-Seok; Chung, Jae-Youn

    2004-09-01

    The methanol extracts of five tropical plants, Baeckea frutescens, Glycyrrhiza glabra, Kaempferia pandurata, Physalis angulata and Quercus infectoria, exhibited potent antibacterial activity against the cariogenic bacterium Streptococcus mutans. In particular, G. glabra, K. pandurata and P. angulata conferred fast killing bactericidal effect against S. mutans in 2 min at 50 microg/ml of extract concentration. PMID:15351117

  14. Influence of ethylenediaminetetraacetic acid (EDTA) on the on the ability of fatty acids to inhibit the growth of bacteria associated with poultry processing.

    Science.gov (United States)

    The effect of ethylenediaminetetraacetic acid (EDTA) on the bactericidal activity of alkaline salts of fatty acids was examined. A 0.5 M concentration of caproic, caprylic, capric, and lauric acids was dissolved in 1.0 M potassium hydroxide (KOH), and then supplemented with 0, 5, or 10 mM of EDTA. T...

  15. Antimicrobial activities of red wine-based formulations containing plant extracts against Escherichia coli O157:H7 and Salmonella enterica serovar Hadar

    Science.gov (United States)

    We evaluated the bactericidal activities of red wine and red wine solutions containing a commercial olive extract called Hydrox-12, oregano oil, or a mixture of both in red wine against the following foodborne pathogens: Escherichia coli O157:H7, Salmonella enterica, Listeria monocytogenes, and Stap...

  16. Evaluation of fusidic acid in therapy of experimental Staphylococcus aureus meningitis

    DEFF Research Database (Denmark)

    Østergaard, Christian; Yieng-Kow, Runa Vavia; Knudsen, Jenny Dahl;

    2003-01-01

    Combination therapy that includes fusidic acid, an antimicrobial agent highly active against staphylococci, has been recommended in the treatment of patients with Staphylococcus aureus meningitis. The aim of this study was to evaluate the pharmacokinetic, CSF bactericidal and anti-inflammatory pr...

  17. Fate of triclosan in agricultural soils after biosolid applications

    Science.gov (United States)

    Triclosan (5-chloro-2-[2,4-dichloro-phenoxy]-phenol (TCS) is a bactericidal compound that is added to a wide variety of household and personal care products. The consumer use of these products releases TCS into urban wastewater and this compound ends up in the environment when agricultural land is ...

  18. In vitro antiplaque activity of octenidine dihydrochloride (WIN 41464-2) against preformed plaques of selected oral plaque-forming microorganisms.

    OpenAIRE

    Slee, A M; O'Connor, J R

    1983-01-01

    The antibacterial activity of octenidine dihydrochloride (WIN 41464-2) against intact preformed in vitro plaques of four indigenous oral plaque-forming microorganisms, Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, and Actinomyces naeslundii, was studied. Both absolute (plaque bactericidal index) and relative (chlorhexidine coefficient) indices of antiplaque efficacy were established. Octenidine dihydrochloride compared favorably with chlorhexidine digluconate with respect...

  19. Recipes for Antimicrobial Wine Marinades against Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica

    Science.gov (United States)

    We evaluated bactericidal activities of several antimicrobial wine recipes consisting of red and white wine extracts of oregano leaves with added garlic juice and oregano oil against Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica. Dose-response plots were...

  20. Relationship between perioperative glycemic control and postoperative infections

    OpenAIRE

    Hanazaki, Kazuhiro; Maeda, Hiromichi; Okabayashi, Takehiro

    2009-01-01

    Perioperative hyperglycemia in critically ill surgery patients increases the risk of postoperative infection (POI), which is a common, and often costly, surgical complication. Hyperglycemia is associated with abnormalities in leukocyte function, including granulocyte adherence, impaired phagocytosis, delayed chemotaxis, and depressed bactericidal capacity. These leukocyte deficiencies are the cause of infection and improve with tight glycemic control, which leads to fewer POIs in critically i...

  1. Volatiles from Coriandrum sativum: comparation of in vitro and ex vitro grown plants

    OpenAIRE

    Cardoso, Susana M.; Dias, I; Sousa, Maria João; Figueiredo, A. Cristina; Barroso, J. G.; Pedro, Luís G.

    2010-01-01

    Coriandrum sativum (coriander) is commonly used, raw or cooked, in Portuguese Gastronomy. Coriander is also used in traditional medicine as a carminative and as a digestive aid. The fruits essential oil is used in food flavouring and in perfumery and is also responsible for the digestive and stimulant effect as well as for fungicide and bactericidal activity.

  2. In vitro activity of azithromycin against clinical isolates of Legionella species.

    OpenAIRE

    Edelstein, P H; Edelstein, M A

    1991-01-01

    The activities of azithromycin, erythromycin, and ciprofloxacin against 21 Legionella isolates were measured by an agar dilution method and in macrophages. The MICs for 90% of strains tested were 2.0, 1.0, and 0.5 micrograms/ml for azithromycin, erythromycin, and ciprofloxacin, respectively. Azithromycin and ciprofloxacin were both bactericidal in the macrophage system, but erythromycin was bacteriostatic.

  3. Multimeric C9 within C5b-9 deposits in unique locations in the cell wall of Salmonella typhimurium

    International Nuclear Information System (INIS)

    We have shown previously that multimeric C9 within C5b-9 (C9:C5b-8 greater than 3:1) is needed for killing of a rough strain of Escherichia coli. We now extend these studies using serum sensitive, rough (R) and serum resistant, wild type (WT) strains of Salmonella typhimurium as well as a mutant S. typhimurium strain (TS) with a temperature sensitive mutation in synthesis of keto-deoxy-octulosonate, a constituent within the deep core structure of Salmonella LPS. Both R and TS required multimeric C9 within C5b-9 to be killed. Addition at 37 degrees C of increasing inputs of C9 to TS or R bearing C5b-9 led to a dose-related increase in C9 binding and killing. In contrast, addition of high inputs of C9 to the same strains at 4 degrees C, a procedure that limits the C9:C5b-8 ratio to 1:1, resulted in low C9 binding and minimal killing. Bactericidal C5b-9 formed at 37 degrees C on R and TS with high inputs of C9 co-sedimented with the bacterial outer membrane on sucrose density gradient analysis. Non-bactericidal C5b-9 on R, WT, and TS co-sedimented near the inner membrane, despite the presumed lack of association between these constituents. Whereas 125I C9 within the non-bactericidal pools immunoprecipitate with anti-C5, 125I C9 within bactericidal pools did not immunoprecipitate with anti-C5, anti-C7, or anti-C9. These findings suggest that bactericidal C5b-9 may be deposited in a unique location or configuration within the bacterial cell wall

  4. Antibacterial activity of DLC films containing TiO2 nanoparticles.

    Science.gov (United States)

    Marciano, F R; Lima-Oliveira, D A; Da-Silva, N S; Diniz, A V; Corat, E J; Trava-Airoldi, V J

    2009-12-01

    Diamond-like carbon (DLC) films have been the focus of extensive research in recent years due to their potential applications as surface coatings on biomedical devices. Titanium dioxide (TiO2) in the anatase crystalline form is a strong bactericidal agent when exposed to near-UV light. In this work we investigate the bactericidal activity of DLC films containing TiO2 nanoparticles. The films were grown on 316L stainless-steel substrates from a dispersion of TiO2 in hexane using plasma-enhanced chemical vapor deposition. The composition, bonding structure, surface energy, stress, and surface roughness of these films were also evaluated. The antibacterial tests were performed against Escherichia coli (E. coli) and the results were compared to the bacterial adhesion force to the studied surfaces. The presence of TiO2 in DLC bulk was confirmed by Raman spectroscopy. As TiO2 content increased, I(D)/I(G) ratio, hydrogen content, and roughness also increased; the films became more hydrophilic, with higher surface free energy and the interfacial energy of bacteria adhesion decreased. Experimental results show that TiO2 increased DLC bactericidal activity. Pure DLC films were thermodynamically unfavorable to bacterial adhesion. However, the chemical interaction between the E. coli and the studied films increased for the films with higher TiO2 concentration. As TiO2 bactericidal activity starts its action by oxidative damage to the bacteria wall, a decrease in the interfacial energy of bacteria adhesion causes an increase in the chemical interaction between E. coli and the films, which is an additional factor for the increasing bactericidal activity. From these results, DLC with TiO2 nanoparticles can be useful for producing coatings with antibacterial properties. PMID:19758597

  5. Antibacterial Effect of CrO and CoFe2O4 Nanoparticles upon Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Saber Imani

    2011-12-01

    Full Text Available Background & Objectives: The use of metal oxide nanoparticles can be effective to eliminate the bacterial infections, as an alternative to antibiotics. In this study, antibacterial properties of nonmaterials of CrO and CoFe2O4 are investigated against Staphylococcus aureus as a major and prevalent pathogenic bacterium to achieve sterile nano-containers. Materials & Methods: Different concentrations of CrO and CoFe2O4 nanoparticles, (0.2, 0.4, 0.6, 0.8, and 1% of each, were examined with respect to their optical density (OD culture separately. Different percentages of each nanoparticles were also examined together for the best antibacterial combination. Kinetics of Bactericidal of nanoparticles were calculated in two-hour periods and were compared with the power of other common antibiotics. Ratios of MIC/MBC were calculated by Micro dilution method, to demonstrate the bactericidal power of nanoparticles. Results: The best concentration of the nanoparticles with the highest effect of bactericidal was obtained in the presence of 1% concentration of CrO that the OD of S. aureus culture medium had reduced 4/6 times than the control group (p<0/001.Ratio of 70% CrO to 30% CoFe2O4 was the best of the Bacteriostatic properties that OD was reduced 3/3 times than the control group (p<0/05. Best kinetics of bactericidal with survival rate in the presence of 1% CrO and CoFe2O4 were obtained in 24 and 36 hours respectively. In critical concentration of 1% CrO and CoFe2O4 bactericidal power was about 67 and 56 % respectively. The MIC/MBC rate for CrO and CoFe2O4 was obtained 0/2 and 0/4 respectively. Conclusion: The results showed that CrO nanoparticle compared with CoFe2O4 has a higher bactericidal power for S. aureus infection. Therefore, by completion of these experiments and the use of metal oxide nanoparticles complex in sensitive environments such as food storage containers, etc. are suggested.

  6. Unearthing the Antibacterial Mechanism of Medicinal Clay: A Geochemical Approach to Combating Antibiotic Resistance

    Science.gov (United States)

    Morrison, Keith D.; Misra, Rajeev; Williams, Lynda B.

    2016-01-01

    Natural antibacterial clays, when hydrated and applied topically, kill human pathogens including antibiotic resistant strains proliferating worldwide. Only certain clays are bactericidal; those containing soluble reduced metals and expandable clay minerals that absorb cations, providing a capacity for extended metal release and production of toxic hydroxyl radicals. Here we show the critical antibacterial components are soluble Fe2+ and Al3+ that synergistically attack multiple cellular systems in pathogens normally growth-limited by Fe supply. This geochemical process is more effective than metal solutions alone and provides an alternative antibacterial strategy to traditional antibiotics. Advanced bioimaging methods and genetic show that Al3+ misfolds cell membrane proteins, while Fe2+ evokes membrane oxidation and enters the cytoplasm inflicting hydroxyl radical attack on intracellular proteins and DNA. The lethal reaction precipitates Fe3+-oxides as biomolecular damage proceeds. Discovery of this bactericidal mechanism demonstrated by natural clays should guide designs of new mineral-based antibacterial agents.

  7. Selection of Streptomyces isolates from Turkish karstic caves against antibiotic resistant microorganisms.

    Science.gov (United States)

    Yücel, Semra; Yamaç, Mustafa

    2010-01-01

    In this work, actinomycetes isolates were isolated from rock wall and speleothem surfaces and soil samples of 19 karstic caves in Turkey. Out of 290 isolates isolated, 180 isolates (62%) exhibited antimicrobial activity against a panel of four bacteria, two yeasts and four filamentous fungi in the screening program. One of them, Streptomyces sp. 1492, was examined for antibiotic production in batch culture. The maximum of antimicrobial activity was shown at 5th day. Antimicrobial activity of the extracted active compound was recorded as dose dependent bacteriostatic or bactericidal against antibiotic resistant clinical bacteria strains; methicillin-resistant Staphylococcus aureus (MRSA), vancomycin resistant Enterobacter faecium (VRE), and Acinetobacter baumanii. Minimum inhibitor concentration and minimum bactericidal concentrations were determined as lower than standard antibiotic streptomycin; 125 microg/ml and 250-1000 microg/ml, respectively. Active component was found as heat-stable. PMID:20067859

  8. Antimicrobial effect against different bacterial strains and bacterial adaptation to essential oils used as feed additives.

    Science.gov (United States)

    Melo, Antonio Diego Brandão; Amaral, Amanda Figueiredo; Schaefer, Gustavo; Luciano, Fernando Bittencourt; de Andrade, Carla; Costa, Leandro Batista; Rostagno, Marcos Horácio

    2015-10-01

    The aim of this study was to evaluate the antimicrobial activity and determine the minimum bactericidal concentration (MBC) of the essential oils derived from Origanum vulgare (oregano), Melaleuca alternifolia (tea tree), Cinnamomum cassia (cassia), and Thymus vulgaris (white thyme) against Salmonella Typhimurium, Salmonella Enteritidis, Escherichia coli, Staphylococcus aureus and Enterococcus faecalis. The study also investigated the ability of these different bacterial strains to develop adaptation after repetitive exposure to sub-lethal concentrations of these essential oils. The MBC of the essential oils studied was determined by disc diffusion and broth dilution methods. All essential oils showed antimicrobial effect against all bacterial strains. In general, the development of adaptation varied according to the bacterial strain and the essential oil (tea tree > white thyme > oregano). Therefore, it is important to use essential oils at efficient bactericidal doses in animal feed, food, and sanitizers, since bacteria can rapidly develop adaptation when exposed to sub-lethal concentrations of these oils. PMID:26424908

  9. Size-dependent antimicrobial properties of sugar-encapsulated gold nanoparticles synthesized by a green method

    Science.gov (United States)

    Badwaik, Vivek D.; Vangala, Lakshmisri M.; Pender, Dillon S.; Willis, Chad B.; Aguilar, Zoraida P.; Gonzalez, Matthew S.; Paripelly, Rammohan; Dakshinamurthy, Rajalingam

    2012-11-01

    The antimicrobial properties of dextrose-encapsulated gold nanoparticles (dGNPs) with average diameters of 25, 60, and 120 nm (± 5) and synthesized by green chemistry principles were investigated against both Gram-negative and Gram-positive bacteria. Studies were performed involving the effect of dGNPs on the growth, morphology, and ultrastructural properties of bacteria. dGNPs were found to have significant dose-dependent antibacterial activity which was also proportional to their size. Experiments revealed the dGNPs to be bacteriostatic as well as bactericidal. The dGNPs exhibited their bactericidal action by disrupting the bacterial cell membrane which leads to the leakage of cytoplasmic content. The overall outcome of this study suggests that green-synthesized dGNPs hold promise as a potent antibacterial agent against a wide range of disease-causing bacteria by preventing and controlling possible infections or diseases.

  10. Unearthing the Antibacterial Mechanism of Medicinal Clay: A Geochemical Approach to Combating Antibiotic Resistance.

    Science.gov (United States)

    Morrison, Keith D; Misra, Rajeev; Williams, Lynda B

    2016-01-01

    Natural antibacterial clays, when hydrated and applied topically, kill human pathogens including antibiotic resistant strains proliferating worldwide. Only certain clays are bactericidal; those containing soluble reduced metals and expandable clay minerals that absorb cations, providing a capacity for extended metal release and production of toxic hydroxyl radicals. Here we show the critical antibacterial components are soluble Fe(2+) and Al(3+) that synergistically attack multiple cellular systems in pathogens normally growth-limited by Fe supply. This geochemical process is more effective than metal solutions alone and provides an alternative antibacterial strategy to traditional antibiotics. Advanced bioimaging methods and genetic show that Al(3+) misfolds cell membrane proteins, while Fe(2+) evokes membrane oxidation and enters the cytoplasm inflicting hydroxyl radical attack on intracellular proteins and DNA. The lethal reaction precipitates Fe(3+)-oxides as biomolecular damage proceeds. Discovery of this bactericidal mechanism demonstrated by natural clays should guide designs of new mineral-based antibacterial agents. PMID:26743034

  11. In vitro antimicrobial activity of pistachio (Pistacia vera L.) polyphenols.

    Science.gov (United States)

    Bisignano, Carlo; Filocamo, Angela; Faulks, Richard M; Mandalari, Giuseppina

    2013-04-01

    We investigated the antimicrobial properties of polyphenol-rich fractions derived from raw shelled and roasted salted pistachios. American Type Culture Collection (ATCC), food and clinical isolates, of Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Pseudomonas mirabilis), Gram-positive bacteria (Listeria monocytogenes, Enterococcus hirae, Enterococcus faecium, Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus), the yeasts Candida albicans and Candida parapsilosis and the fungus Aspergillus niger were used. Pistachio extracts were active against Gram-positive bacteria with a bactericidal effect observed against L. monocytogenes (ATCC strains and food isolates), S. aureus and MRSA clinical isolates. Extracts from raw shelled pistachios were more active than those from roasted salted pistachios. The bactericidal activity of pistachio extracts could be used to help control the growth of some microorganisms in foods to improve safety and may find application as a topical treatment for S. aureus. PMID:23350629

  12. Immunotherapeutic modification of Escherichia coli peritonitis and bacteremia by Tinospora cordifolia.

    Directory of Open Access Journals (Sweden)

    Thatte U

    1992-01-01

    Full Text Available We present here the protective effects of an Indian medicinal plant Tinospora cordifolia as compared to gentamicin in E. Coli induced peritonitis. Pretreatment with tinospora cordifolia or gentamicin reduced mortality in mice injected with 1 x 10(8 E. coli intraperitoneally from 100% in controls to 17.8% and 11.1% respectively. This was associated with significantly improved bacterial clearance as well as improved phagocytic and intracellular bactericidal capacities of neutrophils in the Tinospora cordifolia treated group. In the gentamicin treated mice although bacterial clearance was rapid, polymorph phagocytosis was depressed. Tinospora cordifolia did not possess in vitro bactericidal activity. The results demonstrate that a "prohost approach" may be beneficial in the therapy of peritonitis.

  13. Influence of different rearing systems on natural immune parameters in broiler turkeys.

    Science.gov (United States)

    Franciosini, M P; Bietta, A; Moscati, L; Battistacci, L; Pela, M; Tacconi, G; Davidson, I; Casagrande Proietti, P

    2011-07-01

    The aim of this study was to determine serological values of lysozyme, hemolytic complement levels (alternative pathway), and bactericidal activity of serum in turkeys kept in different rearing systems (industrial, backyard, and experimental). Results showed that the values for serum bactericidal activity and hemolytic complement levels increased with age, and their values were higher in experimental and in industrial turkeys than in turkeys reared in backyard. Lysozyme concentration showed a similar pattern; its value was higher in the industrial and experimental groups than in the backyard group. Data obtained suggest that rearing system can have an influence on the natural immune parameters considered; experimental and industrial groups showed a similar trend, differentiated from that observed in the backyard group. In the backyard group, the values observed may suggest that hybrid turkeys, selected for high production, have difficulty with being reared outside where predators (foxes and weasels) and weather conditions could be responsible for a stress situation. PMID:21673161

  14. Antimicrobial properties of avian eggshell-specific C-type lectin-like proteins.

    Science.gov (United States)

    Wellman-Labadie, Olivier; Lakshminarayanan, Rajamani; Hincke, Maxwell T

    2008-03-01

    C-type lectin-like proteins are major components of the calcified eggshell of multiple avian species. In this study, two representative avian C-type lectin-like proteins, ovocleidin-17 and ansocalcin, were purified from decalcified chicken and goose eggshell protein extracts and investigated for carbohydrate binding activity as well as antimicrobial activity. Purified ovocleidin-17 and ansocalcin were found to bind bacterial polysaccharides, and were bactericidal against Bacillus subtilis, Staphylococcus aureus and Pseudomona aeruginosa. Bactericidal activity was found to be enhanced in the presence of calcium but was not dependent on its presence. The results suggest that avian C-type lectin-like proteins may play an important antimicrobial role in defence of the avian embryo. PMID:18258195

  15. Development of nitrocellulose membrane filters impregnated with different biosynthesized silver nanoparticles applied to water purification.

    Science.gov (United States)

    Fernández, Jorge G; Almeida, César A; Fernández-Baldo, Martín A; Felici, Emiliano; Raba, Julio; Sanz, María I

    2016-01-01

    Bactericidal water filters were developed. For this purpose, nitrocellulose membrane filters were impregnated with different biosynthesized silver nanoparticles. Silver nanoparticles (AgNPs) from Aspergillus niger (AgNPs-Asp), Cryptococcus laurentii (AgNPs-Cry) and Rhodotorula glutinis (AgNPs-Rho) were used for impregnating nitrocellulose filters. The bactericidal properties of these nanoparticles against Escherichia coli, Enterococcus faecalis and Pseudomona aeruginosa were successfully demonstrated. The higher antimicrobial effect was observed for AgNPs-Rho. This fact would be related not only to the smallest particles, but also to polysaccharides groups that surrounding these particles. Moreover, in this study, complete inhibition of bacterial growth was observed on nitrocellulose membrane filters impregnated with 1 mg L(-1) of biosynthesized AgNPs. This concentration was able to reduce the bacteria colony count by over 5 orders of magnitude, doing suitable for a water purification device. PMID:26695258

  16. Antibacterial activity of Rosmarinus officinalis L. alone and in combination with cefuroxime against methicillin-resistant Staphylococcus aureus

    Institute of Scientific and Technical Information of China (English)

    Naser Jarrar; Awni Abu-Hijleh; Kamel Adwan

    2010-01-01

    Objective: To determine the antimicrobial activity of rosemary (Rosmarinus officinalis L.) and to investigate the synergistic effects of this extract combined with ceforuxime against methicillin-resistantStaphylococcus aureus (MRSA).Methods: The inhibitory and bactericidal activities of rosemary ethanol extract, alone and in combination with cefuroxime, were studied.Results: The minimum inhibitory concentrations (MICs) of the ethanol extract of rosemary were in the range of 0.39-3.13 mg/mL. The minimum bactericidal concentrations (MBCs) were usually equal to or double that MICs. The antimicrobial activity of combinations of the ethanol extract of rosemary and cefuroxime indicated their synergistic effects against all MRSAs.Conclusions: The present work clearly demonstrates that rosemary has a key role in the elevation of susceptibility toβ-lactams.

  17. Synthesis and characterization of different structured ZnO nanomaterial through Polyethylene Glycol along with antibacterial activity study by direct attachment to the E.coli Dh5α and S.aureus ATCC 25923 bacterial cell membrane

    Directory of Open Access Journals (Sweden)

    P BHADRA

    2012-09-01

    Full Text Available The development of new resistant strains of bacteria to current antibiotics has become a serious problem in the human health; therefore, there is a strong incentive to develop new bactericides. To overcome this problem Nanotechnology is expected to open new avenues to fight and prevent disease using atomic scale tailoring ofmaterials. Here we achieve the considerable control over ZnO nanomaterials shape comprises volume percentage control of the polymer PEG. In this article, first time we present cuboid like structure to hexagonal disc to columnar structure and finally most challenging tetrapod like structure at room temperature. The products were characterized by several sophisticated instrumental techniques. Zone of inhibition study showed the enhanced biocidal activity of ZnO nanotetrapods compared with other nanostructures in repeatedexperiments. It demonstrated that the bactericidal efficacy of ZnO nanostructures changes with changing nanomaterials structure. Apart from this, we also investigated cell internalization process through SAED pattern.

  18. Preparation, characterization, and antibacterial activity studies of silver-loaded poly(styrene-co-acrylic acid) nanocomposites.

    Science.gov (United States)

    Song, Cunfeng; Chang, Ying; Cheng, Ling; Xu, Yiting; Chen, Xiaoling; Zhang, Long; Zhong, Lina; Dai, Lizong

    2014-03-01

    A simple method for preparing a new type of stable antibacterial agent was presented. Monodisperse poly(styrene-co-acrylic acid) (PSA) nanospheres, serving as matrices, were synthesized via soap-free emulsion polymerization. Field-emission scanning electron microscopy micrographs indicated that PSA nanospheres have interesting surface microstructures and well-controlled particle size distributions. Silver-loaded poly(styrene-co-acrylic acid) (PSA/Ag-NPs) nanocomposites were prepared in situ through interfacial reduction of silver nitrate with sodium borohydride, and further characterized by transmission electron microscopy and X-ray diffraction. Their effects on antibacterial activity including inhibition zone, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and bactericidal kinetics were evaluated. In the tests, PSA/Ag-NPs nanocomposites showed excellent antibacterial activity against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. These nanocomposites are considered to have potential application in antibacterial coatings on biomedical devices to reduce nosocomial infection rates. PMID:24433897

  19. Antimicrobial potential of flavoring ingredients against Bacillus cereus in a milk-based beverage.

    Science.gov (United States)

    Pina-Pérez, Maria C; Rodrigo, Dolores; Martínez-López, Antonio

    2013-11-01

    Natural ingredients--cinnamon, cocoa, vanilla, and anise--were assessed based on Bacillus cereus vegetative cell growth inhibition in a mixed liquid whole egg and skim milk beverage (LWE-SM), under different conditions: ingredient concentration (1, 2.5, and 5% [wt/vol]) and incubation temperature (5, 10, and 22 °C). According to the results obtained, ingredients significantly (pCinnamon was the most bacteriostatic ingredient and cocoa the most bactericidal one when they were added at 5% (wt/vol) and beverages were incubated at 5 °C. The bactericidal effect of cocoa 5% (wt/vol) reduced final B. cereus log10 counts (log Nf, log10 (colony-forming units/mL)) by 4.10 ± 0.21 log10 cycles at 5 °C. PMID:23909775

  20. Disruption of Bacterial Cells by Photocatalysis of Montmorillonite Supported Titanium Dioxide

    Institute of Scientific and Technical Information of China (English)

    LEI Shaomin; GUO Gaoli; XIONG Bihua; GONG Wenqi; MEI Guangjun

    2009-01-01

    The photo-induced antibacterial capacity of montmorillonite supported titanium dioxide(TiO_2/Mmt for short)was evaluated by using Escherichia coli and Staphylococcus aureus as modal organisms.The bactericidal activity of TiO_2/Mmt was examined by cell viability assay under different illumination modes.Atomic force microscopy(AFM)and total organic carbon/Total nitrogen (TOC/TN)analyses were employed to investigate the mechanism of the photocatalytic bactericidal process qualitatively and quantitatively.The kinetic data show that TiO_2/Mmt has excellent antibac-terial performance,and about 99%of both bacteria cells are inactivated within 75 min illumination.The AFM images demonstrate that the bacterial cells are irreversibly decomposed and some cell components are dissolved.Therefore,the content and phase of carbon and nitrogen in the solution are changed after photocatalytic reaction.