Increasing bacterial resistance to common drugs is a major public health concern for the treatment of infectious diseases. Certain naturally occurring compounds of plant sources have long been reported to possess potential antimicrobial activity. This study was aimed to investigate the antibacterial activity and possible mechanism of action of andrographolide (Andro), a diterpenoid lactone from a traditional medicinal herb Andrographis paniculata. Extent of antibacterial action was assessed by minimal bactericidal concentration method. Radiolabeled N-acetyl glucosamine, leucine, thymidine, and uridine were used to determine the effect of Andro on the biosyntheses of cell wall, protein, DNA, and RNA, respectively. In addition, anti-biofilm potential of this compound was also tested. Andro showed potential antibacterial activity against most of the tested Gram-positive bacteria. Among those, Staphylococcus aureus was found to be most sensitive with a minimal inhibitory concentration value of 100 μg/mL. It was found to be bacteriostatic. Specific inhibition of intracellular DNA biosynthesis was observed in a dose-dependent manner in S. aureus. Andro mediated inhibition of biofilm formation by S. aureus was also found. Considering its antimicrobial potency, Andro might be accounted as a promising lead for new antibacterial drug development.

• Keywords
• Andrographolide, Antimicrobial, Bacteriostatic, Biofilm, DNA synthesis,
• MeSH
• Andrographis chemistry   MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Biofilms drug effects   MeSH
• Biosynthetic Pathways drug effects   MeSH
• Diterpenes isolation & purification   pharmacology   MeSH
• DNA biosynthesis   MeSH
• Gram-Positive Bacteria drug effects   physiology   MeSH
• Humans MeSH
• Microbial Sensitivity Tests MeSH
• Microbial Viability drug effects   MeSH
• Plant Extracts isolation & purification   pharmacology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• andrographolide MeSH Browser
• Anti-Bacterial Agents MeSH
• Diterpenes MeSH
• DNA MeSH
• Plant Extracts MeSH

Limited treatment options in infectious diseases caused by resistant microorganisms created the need to search new approaches. Several herbal extracts are studied for their enormous therapeutic potential. Silymarin extract, from Silybum marianum (milk thistle), is an old and a new remedy for this goal. The purpose of this study is to evaluate the antibacterial and antiadherent effects of silymarin besides biofilm viability activity on standard bacterial strains. Minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), antiadherent/antibiofilm activity, and effects on biofilm viability of silymarin were evaluated against standard bacterial strains. MIC values were observed between 60 and >241 μg/mL (0.25->1 mmol/L). Gram-positive bacteria were inhibited at concentrations between 60 and 120 μg/mL. Gram-negative bacteria were not inhibited by the silymarin concentrations included in this study. MBC values for Gram-positive bacteria were greater than 241 μg/mL. Adherence/biofilm formations were decreased to 15 μg/mL silymarin concentration when compared with silymarin-untreated group. Silymarin reduced the biofilm viabilities to 13 and 46 % at 1 and 0.5 mmol/L concentrations, respectively. We demonstrated that silymarin shows antibacterial and antiadherent/antibiofilm activity against certain standard bacterial strains which may be beneficial when used as a dietary supplement or a drug.

• MeSH
• Anti-Bacterial Agents isolation & purification   metabolism   MeSH
• Bacterial Adhesion drug effects   MeSH
• Biofilms drug effects   MeSH
• Gram-Negative Bacteria drug effects   physiology   MeSH
• Gram-Positive Bacteria drug effects   physiology   MeSH
• Microbial Sensitivity Tests MeSH
• Microbial Viability drug effects   MeSH
• Silybum marianum chemistry   MeSH
• Silymarin isolation & purification   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Silymarin MeSH

The activity of antagonistic substances produced by Pseudomonas aeruginosa and Lactobacillus acidophilus against the planktonic and sessile populations of Staphylococcus aureus strains was demonstrated. The strongest effects were caused by probiotic L. acidophilus strain - bacteriocin-like inhibitory substances (BLIS) positive. However, the S. aureus A3 growth, adhesion and biofilm formation was also limited by cell-free supernatant of L. acidophilus H-1 (BLIS negative). Moreover, competitive direct interactions were observed between staphylococci and the above bacteria, which influenced the formation of dualspecies aggregates on the surface.

• MeSH
• Anti-Bacterial Agents metabolism   pharmacology   MeSH
• Antibiosis MeSH
• Bacterial Adhesion drug effects   MeSH
• Bacteriocins metabolism   pharmacology   MeSH
• Biofilms drug effects   MeSH
• Culture Media, Conditioned pharmacology   MeSH
• Lactobacillus acidophilus growth & development   metabolism   physiology   MeSH
• Humans MeSH
• Plankton growth & development   MeSH
• Probiotics MeSH
• Pseudomonas aeruginosa growth & development   metabolism   physiology   MeSH
• Staphylococcus aureus drug effects   growth & development   physiology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Bacteriocins MeSH
• Culture Media, Conditioned MeSH

Staphylococcal hospital isolates (n = 166) were tested in a touchdown multiplex-polymerase chain reaction assay for the identification of methicillin and mupirocin resistance and discrimination of S. aureus (femA gene) from coagulase negative staphylococci and other bacteria. All isolates harbored the 16SrDNA (Staphylococcus genus specific internal control) gene, and 130 (78 %) the mecA (methicillin resistance) gene. Fifty-seven (44 %) of these were determined as methicillin-resistant S. aureus, while the remaining 73 (56 %) were methicillin-resistant coagulase-negative staphylococci. Seventy-five (45 %) isolates harbored the ileS-2 (high-level mupirocin resistance) gene and were determined as mupirocin-resistant. This assay represents a simple, rapid, reliable approach for the detection and discrimination of methicillin-and mupirocin-resistant staphylococci.

• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Bacterial Proteins genetics   metabolism   MeSH
• DNA, Bacterial genetics   MeSH
• Humans MeSH
• Methicillin pharmacology   MeSH
• Drug Resistance, Multiple, Bacterial * MeSH
• Mupirocin pharmacology   MeSH
• Hospitals MeSH
• Polymerase Chain Reaction methods   MeSH
• Methicillin Resistance MeSH
• RNA, Ribosomal, 16S genetics   MeSH
• Sensitivity and Specificity MeSH
• Staphylococcal Infections microbiology   MeSH
• Staphylococcus drug effects   genetics   isolation & purification   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Bacterial Proteins MeSH
• DNA, Bacterial MeSH
• Methicillin MeSH
• Mupirocin MeSH
• RNA, Ribosomal, 16S MeSH

The ability of surfactants obtained from three Lactobacillus acidophilus strains to inhibit Staphylococcus aureus and S. epidermidis biofilms was evaluated. Their influence was determined on bacterial initial adhesion, biofilm formation and dispersal using MTT-reduction assay, confocal laser scanning microscopy and image PHLIP analysis. The number of adhering S. aureus and S. epidermidis cells after a 3-h co-incubation with biosurfactants was reduced by 5-56 % in a strain-and dose-dependent manner. S. epidermidis-and, to a lower extent, in S. aureus-biofilm formation was also inhibited in the presence of the tested surfactants. The addition of surfactants to preformed mature biofilms accelerated their dispersal, and changed the parameters of biofilm morphology. The L. acidophilus-derived surfactants inhibit bacterial deposition rate and biofilm development (and also its maturation) without affecting cell growth probably due to the influence on the cell-surface hydrophobicity of staphylococci.

• MeSH
• Bacterial Adhesion drug effects   MeSH
• Biofilms drug effects   growth & development   MeSH
• Lactobacillus acidophilus metabolism   MeSH
• Humans MeSH
• Surface-Active Agents metabolism   pharmacology   MeSH
• Staphylococcal Infections microbiology   MeSH
• Staphylococcus drug effects   isolation & purification   physiology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Surface-Active Agents MeSH

A total 355 of Staphylococcus cohnii isolates from hospital environment, patients (newborns), medical staff and from non-hospital environment were tested for hemolytic activity. Ninety-one % of S. cohnii ssp. cohnii and 74.5 % S. cohnii ssp. urealyticus strains exhibited hemolysis synergistic to S. aureus ATCC 25923 strain. Crude preparations of hemolysins of both bacterial subspecies presented delta-hemolysin, but not alpha- and beta-toxin activity. Highly pure hemolysins were obtained by semipreparative SDS-PAGE or by organic solvent extraction from the freeze-dried crude preparations. Native-PAGE and 2D-PAGE showed their high heterogeneity. Molar masses of single hemolysin units estimated by the Tris-Tricine-SDS-PAGE were calculated as 3.47 kDa for S. cohnii ssp. cohnii and 3.53 kDa for S. cohnii ssp. urealyticus.

• MeSH
• Adult MeSH
• Electrophoresis, Polyacrylamide Gel MeSH
• Hemolysin Proteins isolation & purification   metabolism   MeSH
• Cross Infection microbiology   MeSH
• Isoelectric Focusing MeSH
• Skin microbiology   MeSH
• Humans MeSH
• Molecular Weight MeSH
• Infant, Newborn MeSH
• Personnel, Hospital MeSH
• Staphylococcal Infections microbiology   MeSH
• Staphylococcus chemistry   isolation & purification   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Infant, Newborn MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Geographicals
• Poland MeSH
• Names of Substances
• Hemolysin Proteins MeSH

Isolates from the "farm to fork" samples (182 isolates from 2779 samples) were examined genotypically (icaAB genes) and phenotypically (in vitro biofilm formation, typical growth on Congo red agar; CRA) with the aim to assess the risk of penetration of virulent strains of Staphylococcus epidermidis into the food chain. The contamination of meat and milk products was significantly higher in comparison with raw materials. Contamination of contact surfaces in the meat-processing plants was significantly lower than that of contact surfaces in the dairy plants. The ica genes (which precondition the biofilm formation) were concurrently detected in 20 isolates that also showed a typical growth on CRA. Two ica operon-negative isolates produced biofilm in vitro but perhaps by an ica-independent mechanism. The surfaces in the dairy plants and the milk products were more frequently contaminated with ica operon-positive strains (2.3 and 1.2 % samples) than the other sample types (0-0.6 % samples).

• MeSH
• Biofilms * MeSH
• Food Contamination * MeSH
• Equipment Contamination MeSH
• Food Handling instrumentation   MeSH
• Meat Products microbiology   MeSH
• Meat microbiology   MeSH
• Dairy Products microbiology   MeSH
• Milk microbiology   MeSH
• Operon MeSH
• Food Microbiology * MeSH
• Electrophoresis, Gel, Pulsed-Field MeSH
• Cattle MeSH
• Staphylococcus epidermidis genetics   isolation & purification   physiology   MeSH
• Virulence MeSH
• Animals MeSH
• Check Tag
• Cattle MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

The occurrence of Staphylococcus aureus in rabbit feces, cecum and meat and its enterotoxin production, susceptibility to antibiotics and its sensitivity or resistance to bacteriocins produced by enterococci with probiotic properties were determined. Isolates were resistant to ampicillin, penicillin, phosphomycin and methicillin; a high percentage of susceptibility was also recorded to vancomycin, chloramphenicol, tetracycline and tobramycin. S. aureus isolates did not produce enterotoxins and were sensitive to partially purified enterocins (PPB) EK13, AL41 and EF2019 in the range of 100 to 12800 AU/mL; all S. aureus isolates, except the strain SA 2A/3, exhibited the highest sensitivity to PPB EK13. On the other hand, all strains were resistant to PPB CCM4231.

• MeSH
• Bacteriocins metabolism   MeSH
• Cecum microbiology   MeSH
• Feces microbiology   MeSH
• Animals, Domestic microbiology   MeSH
• Rabbits MeSH
• Meat microbiology   MeSH
• Microbial Sensitivity Tests MeSH
• Drug Resistance, Multiple, Bacterial * MeSH
• Bridged-Ring Compounds metabolism   MeSH
• Methicillin Resistance * MeSH
• Staphylococcus aureus drug effects   isolation & purification   MeSH
• Animals MeSH
• Check Tag
• Rabbits MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Slovakia MeSH
• Names of Substances
• Bacteriocins MeSH
• enterocin MeSH Browser
• Bridged-Ring Compounds MeSH

During 1999-2005 we treated 15 patients with linezolid for relevant infections of locomotion apparatus (7 cases with endoprosthesis infection, 5x osteomyelitis and 3x another infection). With the exception of one case the antibiotic therapy was always combined with appropriate surgical intervention. Average period of linezolid administration was 26 d; linezolid was applied from the beginning intravenously on average for 10 d, and then orally for 16 d (average). There were no undesirable effects in the file. Success rate reached 86.6%. MRSA strains were proved by standard methods: growth on Mueller-Hinton agar with increased concentration of NaCl and 2 mg/L of oxacilline, and measuring inhibitory zones around cephoxitine disk. The sensitivity to other antibiotics was specified by disk-diffusion test; that to linezolid was verified by E-test. Linezolid represents a medical reserve for the treatment of multiresistant Gram-positive infections or for emergencies, when allergy onset, high toxicity risk, intolerance, etc. do not allow to use other, in vitro effective, antibiotics.

• MeSH
• Acetamides therapeutic use   MeSH
• Anti-Infective Agents therapeutic use   MeSH
• Adult MeSH
• Prosthesis-Related Infections drug therapy   microbiology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Linezolid MeSH
• Microbial Sensitivity Tests MeSH
• Osteomyelitis drug therapy   microbiology   MeSH
• Oxazolidinones therapeutic use   MeSH
• Methicillin Resistance drug effects   MeSH
• Aged MeSH
• Staphylococcal Infections drug therapy   MeSH
• Staphylococcus aureus drug effects   MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Clinical Trial MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Acetamides MeSH
• Anti-Infective Agents MeSH
• Linezolid MeSH
• Oxazolidinones MeSH

The ability of C. parapsilosis (an important cause of nosocomial infections) to produce biofilm was evaluated in 32 bloodstream isolates and 85 strains isolated from skin. The biofilm formation was found in 19 (59%) blood isolates and only in 33 (39%) isolates from skin. The antifungal susceptibility was assessed for amphotericin B, itraconazole and voriconazole in planktonic and biofilm form of the 19 biofilm-positive bloodstream strains by broth microdilution method according to NCCLS standards. The method was modified by the use of resazurin as a colorimetric indicator of the metabolically active cells which makes the determination of the effect of antifungal agents easier. Biofilm forms of all strains were more resistant than their planktonic form.

• MeSH
• Antifungal Agents pharmacology   MeSH
• Biofilms drug effects   MeSH
• Candida drug effects   pathogenicity   MeSH
• Drug Resistance, Fungal drug effects   MeSH
• Fungemia drug therapy   MeSH
• Cross Infection microbiology   MeSH
• Colorimetry MeSH
• Humans MeSH
• Microbial Sensitivity Tests methods   MeSH
• Microbiological Techniques MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antifungal Agents MeSH