Staphylococcus aureus inhibition

EtOAc extract of a marine Bacillus sp. Sc026 culture broth, in bioactivity-guided fractionation, led to the isolation of two new compounds, 7-O-succinyl macrolactin F 229 and 7-(9-succinyl macrolactin A 230. Both exhibited antibacterial activity against Bacillus subtilis and Staphylococcus aureus, (inhibition zones of 8-28 mm at 50-100 pg/disk). 

Staphylococcus aureus inhibited by penicillin and other drugs - ... 

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). 

Small GTPases of the Rho family are ADP-ribosylated (e.g., at Asn4l of RhoA) and inactivated by C3-like toxins from Clostridium botulinum, Clostridium limosum, and Staphylococcus aureus. These proteins have a molecular mass of 23-30 kDa and consist only of the enzyme domain. Specific inhibition of Rho functions (Rho but not Rac or Cdc42 are targets) is the reason why C3 is widely used as a pharmacological tool [2]. 

Oxazolidinones are a new class of synthetic antimicrobial agents, which have activity against many important pathogens, including methicillin-resistant Staphylococcus aureus and others. Oxazolidinones (e.g. linezolid or eperezolid) inhibit bacterial protein synthesis by inhibiting the formation of the 70S initiation complex by binding to the 50S ribosomal subunit close to the interface with the 3OS subunit. 

Deformylation of nascent polypeptides has been shown to be a function essential for growth in E. coli, Staphylococcus aureus and Streptococcus pneumoniae [15-18]. Moreover, antibacterial mode of action studies, using S. pneumoniae or S. aureus strains in which the expression of PDF is controlled by regulatable promoters, have shown that the antibacterial activity of PDF inhibitors is due to their inhibition of the PDF enzyme, as the susceptibility of the strains to these compounds is dependent on the amount of protein present in the cell [19-21]. These results further validate PDF as a target for novel antibiotics. 

Mn2+ active transport system in Staphylococcus aureus. These metal-microbe interactions result in decrease microbial growth, abnormal morphological changes, and inhibition of biochemical processes in individual (Akmal et al. 2005a,b). The toxic effects of metals can be seen on a community level as well. In response to metal toxicity, overall community numbers and diversity decrease. Soil is a living system where all biochemical activities proceed through enzymatic processes. Heavy metals have also adverse effects on enzyme activities (Fig. 1). 

Staphylococcus aureus is known for its ability to produce a variety of toxins and many disease syndromes. One of the most frequently observed diseases is staphylococcal tonsillitis. These bacteria are frequently present on tonsils of healthy carriers. Patients that are affected by tonsillitis swallow staphylococci hidden in tonsil crypts. However, in this case staphylococci do not cause any gastrointestinal symptoms in the host organism, even if they enter the gastrointestinal tract. The barrier of gastric juice and conditions in a small intestine inhibit the outgrowth of staphylococci and toxin production -gastroenteritis is caused solely by a toxin produced outside the host organism. 

Poly(aorylonitrile-co-oxazolidinone), 2 = poly(vinyl aoetate-co-oxazolidinone), 3 = poly(acrylonitrile-g-oxazolidinone), 4 = poly(vinyl aoetate-g-oxazolidinone), 5 = poly(vinyl alcohol-g-oxazolidinone). Coatings were soaked in 3,000 mg/L free ohiorine. Time after ohiorination when biooidal effioaoy was measured. TABLE 2. Zones of inhibition of A/-Chioramine Poiymerio Biooidai Coatings on Fabric against Staphylococcus aureus. ... 

The bacterium Staphylococcus aureus, which is a major cause of infection in the developed countries, is now resistant to most antibiotics. It is usually present on the skin, where it causes no problems, but it can invade the body through cuts and wounds, including those caused by surgery. These bacteria are now prevalent in many hospitals, so that infection is a major problem for the medical staff in hospitals. The resistant bacterium is known as methicillin-resistant Staphylococcus aureus (MRSA). It is also known in the mass media as the super bug . Penicillin kiUs bacteria because the P-lactam group in the antibiotic inhibits a reaction that is essential for bacterial ceU wall production. Consequently, the bacteria cannot proliferate. Resistance to penicillin in many bacteria is due to production of an enzyme, p-lactamase, that degrades P-lactams. The antibiotic methicillin is one of a group of semisynthetic penicillins in which the P-lactam group is not... 

The diazo group confers a broad spectrum of activity on the 2-substi-tuted indoles. In fact, 3-diazo-2-substituted indoles are effective against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhi and Proteus vulgaris bacteria (65MI1), and 3-diazo-2-ethoxycarbo-nylindole inhibits sarcoma 180 in mice and rats (83KFZ1183). 

Some of the organotin-containing polymers inhibit Candias albicans, the yeast responsible for infections in humans better than commercially available applications while leaving the normal flora unharmed. Others inhibit methicillin-resistant Staphylococcus aureus (MRSA) (structure 11.22), preferentially. 

These antibiotics are considered as a choice of last resort where every other antibiotic therapy has failed. The first and only commercially available oxazolidinone antibiotic is linezolid which was introduced in 2002. Its mechanism of action is inhibition of bacterial protein synthesis. It is available for intravenous administration and also has the advantage of having excellent oral bioavailability. Linezolid is used for the treatment of infections caused by multi-resistant bacteria including streptococcus and methicillin-resistant Staphylococcus aureus (MRS A). 

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