In vitro activity of A-16686, a potential antiplaque agent

Abstract

A-16686, a new glycoproteide antibiotic from Actinoplanes sp., was evaluated as a potential antiplaque agent in comparison with chlorhexidine, benzalkonium chloride, and cetylpyridinium chloride. A-16686 had good activity against gram-positive organisms associated with dental plaque (various streptococci, Streptococcus mutans in particular, lactobacilli, Actinomyces viscosus, and Actinomyces naeslundi); most of the strains tested were clinical isolates. It was bactericidal for streptococci (MBC/MIC ratio of <8 for 92% of the strains) and for growing cells of S. mutans briefly exposed to antibiotic (99.9% killing within 5 min of contact with 200 ,g of A-16686 per ml). It also inhibited the in vitro plaque formation by S. mutans and had good activity against preformed plaques. For most cases, its activity was comparable to those of chlorhexidine, benzalkonium chloride, and cetylpyridinium chloride. A-16686 appears to be a promising antiplaque agent because of the following attributes: narrow spectrum of activity, rapid bactericidal action, lack of selection of resistant mutants, absence of cross-resistance with clinicaDly used antibiotics, nonabsorption by oral route, good tolerability by the oral mucosa (rats and dogs), and physical characteristics (white powder, soluble in water).

Antibacterial effects of three experimental quaternary ammonium salt (QAS) monomers on bacteria associated with oral infections

“…The MBC values for DMAE-CB with the four oral pathogenic bacterial strains were within the range 2.4~9.6 µg/ml (5.75~22.99 µM), while those of the other two monomers were within 1562.5~6250.0 µg/ml (5.51~22.04×10 3 µM for DMAE-BC, and 4.91~19.65×10 3 µM for DMAE-m-CBC). Therefore, the MBC value for DMAE-CB was in accordance with those of the representative QAS species, cetylpyridinium chloride (CPC) and benzalkonium chloride (BKC), which have been reported to be 1~8 and 2~8 µg/ml, respectively (22).…”

In vitro Activity of A-16686, a New Glycopeptide

“…Penicillin, erythro mycin and methicillin were obtained from commer cial sources. (2) 0.5 Proprionibacterium acnes (4) 0.03-2 Actinomyces (5) 0.125-0.5…”

“…It is possible that topical application of a potent anti microbial agent which did not lead to de velopment of resistance would be helpful in controlling gingivitis and caries. Pallanza et al [4] recently reported on the ac tivity of a new glycopeptide antibiotic, A-16686, derived from Actinoplanes. We wished to evaluate its activity against aer obic and anaerobic species in comparison to other antimicrobial agents.…”

In vitro activities of ramoplanin and four glycopeptide antibiotics against clinical isolates of Clostridium difficile

“…Of course, since the National Committee for Clinical Laboratory Standards reference method is not designed for testing topical agents, caution is necessary in extrapolating the results of MIC assays when interpreting topical activity. However, several properties of ramoplanin are consistent with its promising future use as a topical agent, including good local tolerability in animal models, narrow spectrum of activity, rapid bactericidal action, no selection of resistant mutants, no cross-resistance with clinically used antibiotics, no oral absorption, and favorable comparison with mupirocin and other topical antibacterial agents (6,9,23). Prospective clinical trials for the evaluation of ramoplanin in the treatment of C. difficileassociated disease are warranted and strongly urged.…”

“…Furthermore, ramoplanin inhibits cell wall synthesis at a site different from that inhibited by glycopeptides, probably acting on the second stage of the biosynthetic pathway at the level of lipid intermediate formation or utilization (26). Ramoplanin is unlikely to be developed for systemic use because it is poorly tolerated after intravenous or intramuscular administration (1), but it is considered very promising for topical use, especially as an antiplaque (23) or an antiacne (22) agent, for clearing staphylococci from carriage sites (9), or for treating other superficial infections in which gram-positive bacteria are involved (6). Of course, since the National Committee for Clinical Laboratory Standards reference method is not designed for testing topical agents, caution is necessary in extrapolating the results of MIC assays when interpreting topical activity.…”