Staphylococcus aureus antibacterial properties

Echinomycin (131) has been shown to be an antitumor agent and to have antiviral and antibacterial properties. Its structure elucidation represents a triumph for and mass spectral studies (75JA2497). It has been demonstrated that echinomycin functions by inhibiting RNA synthesis in organisms such as Staphylococcus aureus. Echinomycin, levomycin and actinoleutin are members of the quinoxaline-peptide antibiotic family and all contain one or more quinoxaline rings (67MI21402). 

In 2000, a new family of /V-methylthio-substituted p-lactams having promising antibacterial properties has been identified by Turos and coworkers. Curiously, most of this activity is directed towards Staphylococcus bacteria, including methi-cillin-resistant strains of Staphylococcus aureus (MRSA). These p-lactams showed... 

The antibacterial effect of honey derived from Kanuka and Manuka blossom against Staphylococcus aureus was shown and, more recently, Manuka honey was shown to be active against Helicobacter pylori. Leptospermum scoparium contains leptospermone, which has antihelminthic properties and is closely related to compounds having similar properties in male ferns leptospermone has insecticidal properties, and is similar in structure to the insecticide valone. 

Nablo et al. were the first to evaluate the antibacterial properties of NO-releasing xerogels using Pseudomonas aeruginosa and Staphylococcus aureus as... 

The prototypical lantibiotic, nisin, was discovered in 1928 for its antibacterial properties and has been used as a preservative in dairy products since the 1950s (1). Nisin and other lantibiotics exhibit nanomolar efficacy against many Gram-positive strains of bacteria (2), which include methicillin resistant Staphylococcus aureus, vancomycin resistant enterococci, and oxacillin resistant bacteria. On the other hand, some lantibiotics function as morphogenetic peptides rather than antibiotics and are important for spore formation in streptomycetes (3). Since the structural elucidation of nisin in the early 1970s, extensive research efforts have been directed at understanding the biosynthesis and mode of action of various lantibiotics. 

Tea tree oil is extracted from Melaleuca alternifolia, a plant that is native to Australia. It is considered to have antibacterial properties, including an effect on methicil-lin-resistant Staphylococcus aureus (MRSA), while the commensal flora of the skin seem to be less susceptible (1). In addition, it is said to have antifungal, antiviral, anti-inflammatory, and analgesic properties, and has been increasingly incorporated into cosmetics for aromatherapy. 

Antimicrobial activity similar to imidurea. " Diazolidinyl urea is the most active of the imidazolidinyl family of preservatives. Used in concentrations of 0.1-0.5% w/w, at pH 3-9, it has predominantly antibacterial properties. Typical MICs are Aspergillus niger 4000 pg/mL Candida albicans 8000 pg/mL Escherichia coli 1000 pg/mL Pseudomonas aeruginosa lOOOpg/mL Staphylococcus aureus 250 pg/mL. 

From the roots of Chaptalia nutans (L.) Polak., a plant traditionally used in Brazilian folk medicine, Truiti et al. [240] isolated the pure compound 7-O-P-D-glucopyranosyl-nutanocoumarin. The compound inhibited Bacillus subtilis and Staphylococcus aureus at concentrations of 62.5 g/ml and 125 g/ml, respectively. The antibacterial property of Chaptalia nutans appears to justify its use for the treatment of wounds which are contaminated through bacterial infections. 

St. John s wort has been used topically for wound healing for hundreds of years. Antibacterial properties have been reported as early as 1959, with hyperforin found to be the active component. Using multiple concentrations, it was discovered that no hyperforin dilutions had antimicrobial effects on Gram-negative bacteria or Candida albicans. There was, however, growth inhibition for all of the Gram-positive bacteria tested, some with the lowest dilution concentration of 0.1 pg/mL. Hyperforin was also shown to be effective at inhibiting methacillin-resistant Staphylococcus aureus (25). 

Tamarind fruits are reported to have anti-fungal and anti-bacterial properties (Ray and Majumdar, 1976, Guerin and Reveillere, 1984, Bibitha et al, 2002, Metwali, 2003, and John et al, 2004, all cited in (5)). According to Al-Fatimi and collaborators 11), in an agar diffusion assay, extracts from T. indica flowers showed antibacterial activity against four bacteria tested Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa). Antimicrobial activity of T. indica study has been attributed to lupeol (Ali et al, 1998, cited in 11)). 

PP/silver nanocomposite fibres were prepared with the aim of achieving permanent antibacterial activity in a common synthetic textile. The fibres were melt-spun by coextmsion of PP and PP/silver masteibatches using general conjugate spinning. Masteibatches were made up of a mixture of PP chips and nano-sized silver powder. The antibacterial efficacy of spun fibres was high when the masteibatch was used as the sheath rather than the core. The antibacterial activity of nano-silver in fibres was evaluated after a certain contact time and calculated by percent reduction of two types of bacteria. Staphylococcus aureus and Klebsiela pneumoniae. DSC and wide-angle X-ray diffraction were used for analysis of stractuie, thermal properties and crystallisation behaviour of the spun fibres. SEM was carried out in order to observe particle distribution on the nanocomposite fibres. 17 refs. (2nd International Conference on Polymer Fibres, Manchester, UK, July 2002)... 

The biocidal activities of a series of quatemised PUs were examined a inst Staphylococcus aureus and E.coli. The effect of quatemisation on material properties was examined with tensile testing, water absorption analysis, and contact angle measurements. The antibacterial action of the polymers was investigated. 19 refs. 

The antibacterial properties of MgO powder has been studied by Sawai et al. (2000) and has been found to have antibacterial activity toward Escherichia coli and Staphylococcus aureus. It was found that contact between the bacterial cells and the MgO powder was necessary for the bactericidal activity. It is speculated that the generation of active oxygen species, such as O, which was found to be produced by MgO powder, may be the primary factor in its antibacterial activity rather than any effect due to increasing the growth medium pH caused by the MgO. 

The two preparations from H. perforatum, novoimanine, the 0.25% aqueous alcoholic solution, and imanine, the water soluble fraction showed antibacterial properties against Staphylococcus aureus [93], Chemical analysis of novoimanine showed that the main extractives consisted with phenolic glycosides of low polarity [94]. 

An antibacterial assay using the disc-diffusion method found that the stems and the roots of H. capitellata showed weak to moderate activities against the tested bacteria, Bacillus subtilis B28, Bacillus subtilis B29, Pseudomonas aeruginosa UI 60690 and methicillin resistant Staphylococcus aureus, (MRSA) while the leaves showed weak activity toward Bacillus subtilis B28, MRSA and P. aeruginosa only. However, the roots of H. dichotoma showed moderate antibacterial properties against all four bacteria. All other extracts did not exhibit any antibacterial properties. Table 10 shows the inhibition zones of the methanolic extracts of some Hedyotis species as measured by the disc-diffusion method. 

The simplest form of a Free Wilson analysis is presented in eq. 192 [22], which describes the antibacterial activities of phenol and isomeric chlorophenols (51, R = H, Cl one to five chlorine atoms) vs. Staphylococcus aureus at least the linearity of the structure-activity relationship can be derived from eq. 192 on the other hand, although most probably lipophilicity is responsible for the variance in the biological activities, no Hansch equation can be derived, because each other physicochemical property of the chlorine atom will give identical results. 

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