Biofilms are communities of surface-associated bacteria or fungi embedded in a self-produced extracellular polymeric matrix that are notoriously difficult to be eradicated and are sources of many recalcitrant infections. Treatment for biofilm infection with any individual drug is always less effective, while the combinations of different types of drugs are superior to monotherapy concerning the removing of biofilms. This paper focus on research progress in recent years for synergistic effect of drugs in combination against biofilms formed by Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Candida albicans.
Anti-Bacterial Agents ; pharmacology ; Antifungal Agents ; pharmacology ; Bacteria ; drug effects ; Biofilms ; drug effects ; growth & development ; Candida albicans ; drug effects ; Escherichia coli ; drug effects ; Pseudomonas aeruginosa ; drug effects ; Staphylococcus aureus ; drug effects ; Staphylococcus epidermidis ; drug effects

OBJECTIVETo study the effect of DNase I on biofilm formation of Staphylococcus aureus.

METHODSThe growth curve of S. aureus was detected using a spectrophotometer. The adhesion of S. aureus was analyzed using flat colony counting method, and the biofilm formation was assayed using the 96-well crystal violet staining method.

RESULTSExposure to different concentrations of DNase I did not obviously affect the growth of S. aureus but significantly inhibit the formation of bacterial biofilms in a dose-dependent manner. DNase I inhibited the adhesion of S. aureus at different growth stages. When combined with antibiotics, DNase I resulted in a signi?cant decrease in the established bio?lm biomass compared to antibiotics or DNase I used alone.

CONCLUSIONDNase I can effectively inhibit biofilm formation of S. aureus and enhance the inhibitory effect of antibiotics against S. aureus biofilms.

Anti-Bacterial Agents ; Biofilms ; drug effects ; Deoxyribonuclease I ; chemistry ; Staphylococcus aureus ; growth & development

The standard iron-chelator deferoxamine is known to prevent the growth of coagulase-negative staphylococci (CoNS) which are major pathogens in iron-overloaded patients. However, we found that deferoxamine rather promotes the growth of coagulase-positive Staphylococcus aureus. Accordingly, we tested whether deferiprone, a new clinically-available iron-chelator, can prevent the growth of S. aureus strains as well as CoNS. Deferiprone did not at least promote the growth of all S. aureus strains (n=26) and CoNS (n=27) at relatively low doses; moreover, it could significantly inhibit the growth of all staphylococci on non-transferrin-bound-iron and the growth of all CoNS on transferrin-bound iron at relatively high doses. At the same doses, it did not at least promote the growth of all S. aureus strains on transferrin-bound-iron. These findings indicate that deferiprone can be useful to prevent staphylococcal infections, as well as to improve iron overload, in iron-overloaded patients.
Deferoxamine/pharmacology ; Humans ; Iron/metabolism ; Iron Chelating Agents/*pharmacology ; Iron Overload/metabolism ; Microbial Sensitivity Tests ; Pyridones/*pharmacology ; Staphylococcus/*drug effects/growth & development ; Staphylococcus aureus/drug effects/growth & development ; Transferrin/metabolism

OBJECTIVETo study and analyze the antibacterial effects of different extracts from Radix Isatis.

METHODSStaphylococcus aureus was used as the studied object in the experiment. Antibacterial effects of extracts from Radix Isatis were observed by thermocalrimetry on Staphylococcus aureus, together with common pharmacological experiments.

RESULTSThe total extract, ethyl acetate (EtOAc) extract, n-butylalcohol (nBuOH) extract, chloroform (CHCl(3)) extract and petroleum (P.E.) extract had antiviral effects to some extent while the residue after extracting had no antibacterial activity. The potency of antiviral activity among them was as follows: nBuOH extract > EtOAc extract > CHCl(3) extract > total extract > P.E. extract.

CONCLUSIONThe antibacteriall effects of Radix Isatis were not limited to any active portion, showing that Radix Isatis exerts its antibacterial effects by cooperation of different active fractions in varied ways.

Anti-Bacterial Agents ; pharmacology ; Calorimetry ; Isatis ; Microbial Sensitivity Tests ; Plant Extracts ; pharmacology ; Plant Roots ; Staphylococcus aureus ; drug effects ; growth & development

OBJECTIVETo observe the effect of the combination of sub-MIC sodium houttuyfonate and erythromycin on biofilm of Staphylococcus epidermidis.

METHODThe serial dilution method was adopted to determine MIC of the combination of sodium houttuyfonate and erythromycin on S. epidermidis; the checkerboard method was used to evaluate the combination of sodium houttuyfonate and erythromycin on suspended bacteria of S. epidermidis; S. epidermidis biofilm was built in vitro, and XTT reduction assay was used to evaluate the effect of the combination of sub-MIC sodium houttuyfonate and erythromycin on the adhesion of S. epidermidis and bacterial metabolism inside the biofilm. Microscope was applied to observe the impact the single administration and combination of the two medicines under sub-MIC on biofilm morphology of S. epidermidis.

RESULTThe MIC of sodium houttuyfonate and erythromycin were 62.5, 7.812 5 mg x L(-1), respectively. The combination of 1/8MIC sodium houttuyfonate and 1/2MIC erythronmycin showed a synergistic effect on S. epidermidis. Sodium houttuyfonate, erythromycin and their combination had an inhibitory effect on the adhesion and metabolism of S. epidermidis biofilm bacteria, and made impact on the morphology of S. epidermidis biofilm.

CONCLUSIONThe sub-MIC sodium houttuyfonate and erythromycin have an inhibitory effect on S. epidermidis biofilm. The combination of sodium houttuyfonate and erythromycin shows a synergistic effect in inhibiting suspended bacteria and biofilm of S. epidermidis, particularly in inhibiting the metabolism of S. epidermidis biofilm bacteria and impacting the morphology of biofilm.

Alkanes ; pharmacology ; Anti-Bacterial Agents ; pharmacology ; Bacterial Adhesion ; drug effects ; Biofilms ; drug effects ; growth & development ; Dose-Response Relationship, Drug ; Drug Interactions ; Erythromycin ; pharmacology ; Microbial Sensitivity Tests ; Staphylococcus epidermidis ; drug effects ; physiology ; Sulfites ; pharmacology

In order to obtain a high activity antibacterial peptide, An expression vector pPICZalphaA-pl is constructed with a tandem of four antimicrobial peptides in the same direction,which includes Protegrin-1 (PG-1), Scorpion Defensin (SD), Metalnikowin-2A and Sheep Myeloid Antibacterial Peptide (SMAP-29) (serial number in GenBank are AAB27599, AAAB27538, P80409 and P49928 respectively). At the same time the expression vector pPICZalphaA-sd which express Scorpion Defensin was contructed. The expression vectors of pPICZalphaA-pl and pPICZalphaA-sd were linearized and transformed into the yeast host strain X-33 respectively. Under the control of the promoter AOX1 (alcohol oxidase1), the peptides PL and SD were secreted expressed. Their heat-stable property, acid-stable property and MIC were detected in vitro. The results suggest the peptides PL and SD have good heat-stable and acid-stable properties, and the combinant PL peptide showes higher antibacterial activity against several Gram-positive bacteria (G+) and Gram-negative bacteria (G-) than the peptide SD, especially against Escherichia coli. The antibacterial activity of combinant antimicrobial peptide PL shows its far exploiting perspective.
Animals ; Anti-Infective Agents ; metabolism ; pharmacology ; Antimicrobial Cationic Peptides ; genetics ; pharmacology ; secretion ; Bacillus subtilis ; drug effects ; growth & development ; Blood Proteins ; genetics ; pharmacology ; secretion ; Cathelicidins ; Defensins ; genetics ; pharmacology ; secretion ; Electrophoresis, Polyacrylamide Gel ; Escherichia ; drug effects ; growth & development ; Hydrogen-Ion Concentration ; Pichia ; genetics ; Recombinant Fusion Proteins ; genetics ; pharmacology ; secretion ; Salmonella ; drug effects ; growth & development ; Scorpions ; metabolism ; Sheep ; metabolism ; Staphylococcus aureus ; drug effects ; growth & development ; Time Factors

OBJECTIVESThis study aimed to evaluate the in vitro antioxidant capacity, to determine the anti-inflammatory effect due to lipoxygenase inhibition and to test the antimicrobial activity of ethanolic extracts from leaves of seven climbing species belonging to the Bignoniaceae family. These species are Adenocalymma marginatum (Cham.) DC., Amphilophium vauthieri DC., Cuspidaria convoluta (Vell.) A. H. Gentry, Dolichandra dentata (K. Schum.) L. G. Lohmann, Fridericia caudigera (S. Moore) L. G. Lohmann, Fridericia chica (Bonpl.) L. G. Lohmann and Tanaecium selloi (Spreng.) L. G. Lohmann.

METHODSThe antioxidant activity was evaluated using three methods, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power. Lipoxygenase-inhibiting activity was assayed spectrophotometrically; the result was expressed as percent inhibition. The antimicrobial activity was assessed using the agar disk diffusion method. Minimal inhibitory concentration (MIC) and minimal bactericidal/fungicidal concentration were also determined for each extract against 12 pathogenic bacterial strains of Staphylococcus aureus and seven fungal strains of the Candida genus. The identification of the major compounds present in the most promising extract was established by high-performance liquid chromatography-tandem mass spectrometry.

RESULTSC. convoluta, F. caudigera, and F. chica exhibited the best antioxidant activity by scavenging DPPH and ABTS radicals and reducing Fe ion. These extracts showed a notable inhibition of lipoxygenase. F. caudigera was found to have the lower MIC value against S. aureus strains and six Candida species. The extracts of F. caudigera and C. convoluta were active even against methicillin-resistant S. aureus. C. convoluta had higher total phenol content, better antioxidant activity and superior anti-inflammatory and antimicrobial activity. The main phenolic compounds found in this extract were coumaric and hydroxybenzoic acid derivatives and glycosylated and nonglycosylated flavones.

CONCLUSIONMost of the extracts exhibited antioxidant activity as well as in vitro inhibition of lipoxygenase. The excellent antimicrobial activity of T. selloi and F. chica supports their use in traditional medicine as antiseptic agents. The extracts of F. caudigera and C. convoluta, both with notable biological activities in this study, could be used as herbal remedies for skin care. In addition, this study provides, for the first time, information about phenolic compounds present in C. convoluta.

Anti-Infective Agents ; chemistry ; pharmacology ; Antioxidants ; chemistry ; pharmacology ; Bignoniaceae ; chemistry ; Candida ; drug effects ; growth & development ; Humans ; Lipoxygenase ; chemistry ; Lipoxygenase Inhibitors ; chemistry ; pharmacology ; Medicine, Traditional ; Microbial Sensitivity Tests ; Plant Extracts ; chemistry ; pharmacology ; Staphylococcus aureus ; drug effects ; growth & development

OBJECTIVEThis study examined the antimicrobial activity of Cannabis sativa, Thuja orientalis and Psidium guajava against methicillin-resistant Staphylococcus aureus (MRSA) and used a standardized purification protocol to determine the presence and abundance of bioactive compounds in the leaf extracts.

METHODSIn vitro antimicrobial activities of the ethanolic extracts of C. sativa, T. orientalis and P. guajava were tested against MRSA. The presence of bioactive molecules in these three leaves was evaluated using biochemical assays and high-performance thin-layer chromatography (HPTLC).

RESULTSResistance to methicillin, penicillin, oxacillin and cefoxitin was observed in each of the clinical and nonclinical MRSA isolates. However, they were still vulnerable to vancomycin. Used individually, the 50% extract of each plant leaf inhibited MRSA growth. A profound synergism was observed when C. sativa was used in combination with T. orientalis (1:1) and when P. guajava was used in combination with T. orientalis (1:1). This was shown by larger zones of inhibition. This synergism was probably due to the combined inhibitory effect of phenolics present in the leaf extracts (i.e., quercetin and gallic acid) and catechin, as detected by HPTLC.

CONCLUSIONThe leaf extracts of C. sativa, T. orientalis and P. guajava had potential for the control of both hospital- and community-acquired MRSA. Moreover, the inhibitory effect was enhanced when extracts were used in combination.

Anti-Bacterial Agents ; pharmacology ; Cannabis ; Drug Resistance ; drug effects ; Humans ; Methicillin ; pharmacology ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; growth & development ; Microbial Sensitivity Tests ; Phytotherapy ; Plant Extracts ; pharmacology ; Plant Leaves ; Psidium ; Staphylococcal Infections ; drug therapy ; microbiology ; Thuja

Through our pre-investigation and literature analysis, it was found that rhubarb could be categorized into two types, chrysophanol-type and rhein-type, based on the proportion of the two constituents in the total content of anthraquinones after acid hydrolysis. In this paper, the antimicrobial activities of chrysophanol-type and rhein-type rhubarbs against Staphylococcus aureus were compared with microcalorimetric analysis, in order to illustrate the bioactive differentiability between the two chemotypes. For the aim to display the distinction of chrysophanol and rhein percentage in total anthraquinones, the sampling volume was regulated to make the total anthraquinones equivalent, thus, the antimicrobial difference was only attributed to the difference of chemotypes. The results indicated that the antimicrobial difference between the two chemotypes was confirmable labeled at the biothermokinetic parameters of S. aureus growth affected by the rhubarb samples. The growth rate constant (k1) of the first exponential phase for the growth of S. aureus affected by the rhein-type rhubarb was significantly lower than that of chrysophanol-type (P<0.01), which suggested stronger antimicrobial activity of rhein-type rhubarb than that of chrysophanol-type. However, the antimicrobial activities of rhein-type rhubarbs were not positively correlated to the contents of rhein. It suggested that the antimicrobial activity of rhubarb might be related to some unknown components which were of same accumulating pattern of rhein. The findings in present study provided some experimental evidence on categorizing rhubarb into two chemotypes through the difference of antimicrobial activity on S. aureus by microcalorimetric analysis and, further, offered references to revision of the commercial specification of rhubarb from chemical view.
Anthraquinones ; isolation & purification ; pharmacology ; Anti-Infective Agents ; isolation & purification ; pharmacology ; Calorimetry ; Plants, Medicinal ; chemistry ; Rheum ; chemistry ; Staphylococcus aureus ; drug effects ; growth & development

This study aimed to develop a guideline for therapeutic drug monitoring (TDM) of vancomycin. We adopted the new guideline definition from the Institute of Medicine (IOM), adhered closely to the six domains of the Appraisal of Guidelines for Research & Evaluation II (AGREE II), and made recommendations based on systematic reviews. We established a Guideline Steering Group and a Guideline Development Group, formulated 12 questions in the form of Population, Intervention, Comparison, Outcome (PICO) and completed a literature search. As far as we know, we will develop the first evidenced-based guideline for vancomycin TDM under the framework of the Grade of Recommendations Assessment, Development and Evaluation (GRADE).
Anti-Bacterial Agents ; administration & dosage ; economics ; pharmacokinetics ; China ; Drug Administration Schedule ; Drug Monitoring ; methods ; Evidence-Based Medicine ; Humans ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; growth & development ; pathogenicity ; Staphylococcal Infections ; drug therapy ; microbiology ; pathology ; Vancomycin ; administration & dosage ; economics ; pharmacokinetics