Combined effect of a mixture of tetracycline, acid, and detergent, and Nisin against Enterococcus faecalis and Actinomyces viscosus biofilms

To evaluate the combined effect of a mixture of tetracycline, acid, and detergent [MTAD] and Nisin against Enterococcus faecalis [E. faecalis] and Actinomyces viscosus [A. viscosus] biofilms. This study was conducted between June and December 2013 in collaboration with Dental Caries Research Chair, College of Dentistry, King Saud University, Riyadh, Saudi Arabia. Single-species biofilms [n=9/species/observation period] were generated on membrane filter discs and subjected to 5, 10, or 15 minute incubation with MTADN [MTAD with 3% Nisin], 5.25% sodium hypochlorite [NaOCl], or normal saline. The colony forming units were counted using the Dark field colony counter. A 100% bactericidal effect of 5.25% NaOCl was noted during the 3 observation periods; a significant reduction [p=0.000] in mean survival rates of E. faecalis [77.3+13.6] and A. viscosus [39.6+12.6] was noted after 5 minutes exposure to MTADN compared with normal saline [78000000+5291503] declining to almost no growth after 10 and 15 minutes. The survival rates of the E. faecalis and A. viscosus biofilm were no different after treatment with MTADN and 5.25% NaOCl at the 3 observation periods [p=1.000]. A combination of MTAD and Nisin was as effective as NaOCl against E. faecalis and A. viscosus biofilms

Cutaneous actinomycosis: a rare case.

Cutaneous actinomycosis is a rare presentation. Here we present a case of cutaneous actinomycosis with no history of trauma or systemic dissemination. The isolate was identified as Actinomyces viscosus by standard methods. The isolate was found to be penicillin resistant by Kirby Bauer disc diffusion method. Therefore, the patient was treated with cotrimoxazole and improved. Thus, this case highlights the importance of isolation and susceptibility testing in actinomycotic infection. The sinuses have healed, and the patient has recovered.