Synthesis, characterization, and antimicrobial activity of silver carbene complexes derived from 4,5,6,7-tetrachlorobenzimidazole against antibiotic resistant bacteria.
ABSTRACT Silver N-heterocyclic carbene complexes have been shown to have great potential as antimicrobial agents, affecting a wide spectrum of both Gram-positive and Gram-negative bacteria. A new series of three silver carbene complexes (SCCs) based on 4,5,6,7-tetrachlorobenzimidazole has been synthesized, characterized, and tested against a panel of clinical strains of bacteria. The imidazolium salts and their precursors were characterized by elemental analysis, mass spectrometry, (1)H and (13)C NMR spectroscopy, and single crystal X-ray diffraction. The silver carbene complexes, SCC32, SCC33, and SCC34 were characterized by elemental analysis, (1)H and (13)C NMR spectroscopy, and single crystal X-ray diffraction. These complexes proved highly efficacious with minimum inhibitory concentrations (MICs) ranging from 0.25 to 6 μg mL(-1). Overall, the complexes were effective against highly resistant bacteria strains, such as methicillin-resistant Staphylococcus aureus (MRSA), weaponizable bacteria, such as Yersinia pestis, and pathogens found within the lungs of cystic fibrosis patients, such as Pseudomonas aeruginosa, Alcaligenes xylosoxidans, and Burkholderia gladioli. SCC33 and SCC34 also showed clinically relevant activity against a silver-resistant strain of Escherichia coli based on MIC testing.
- Burns 04/2000; 26(2):117-30. · 1.80 Impact Factor
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ABSTRACT: In 1965, Moyer revived interest in silver nitrate solution. He concluded on the basis on in vitro and in vivo studies that a 0.5% solution represented the lowest concentration at which antibacterial action (against Staphylococcus aureus, haemolytic streptococci and generally against Pseudomonas aeruginosa and E. coli) was obtained. Mafenide acetate was introduced a short time after the reintroduction of silver nitrate, followed a few years later by silver sulphadiazine. Thus, in a short period of time three medicaments appeared on the market which represented a radical change in the topical treatment of burns. The action of silver sulphadiazine has been intensively studied. Since silver sulphadiazine does not offer sufficient protection to prevent or retard the growth of gram-negative bacteria in patients with burns covering more than 50% of body surface, Monafo introduced the combined preparation silver sulphadiazine and cerium nitrate. Although various attempts have been made to develop more effective silver compounds, so far silver sulphadiazine still remains the most widely used substance of this type.Burns 04/2000; 26(2):131-8. · 1.80 Impact Factor
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ABSTRACT: The pressing need to treat multi-drug resistant bacteria in the chronically infected lungs of cystic fibrosis (CF) patients has given rise to novel nebulized antimicrobials. We have synthesized a silver-carbene complex (SCC10) active against a variety of bacterial strains associated with CF and chronic lung infections. Our studies have demonstrated that SCC10-loaded into L-tyrosine polyphosphate nanoparticles (LTP NPs) exhibits excellent antimicrobial activity in vitro and in vivo against the CF relevant bacteria Pseudomonas aeruginosa. Encapsulation of SCC10 in LTP NPs provides sustained release of the antimicrobial over the course of several days translating into efficacious results in vivo with only two administered doses over a 72 h period.Biomaterials 05/2009; 30(22):3771-9. · 7.60 Impact Factor