Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2011 Sep;55(9):4211-7.
doi: 10.1128/AAC.00561-11. Epub 2011 Jul 11.

In vitro antibacterial activity of NB-003 against Propionibacterium acnes

J Pannu  1 , A McCarthy, A Martin, T Hamouda, S Ciotti, L Ma, J Sutcliffe, J R Baker Jr
Affiliations

In vitro antibacterial activity of NB-003 against Propionibacterium acnes

J Pannu et al. Antimicrob Agents Chemother. 2011 Sep.

Abstract

NB-003 and NB-003 gel formulations are oil-in-water nanoemulsions designed for use in bacterial infections. In vitro susceptibility of Propionibacterium acnes to NB-003 formulations and comparator drugs was evaluated. Both NB-003 formulations were bactericidal against all P. acnes isolates, including those that were erythromycin, clindamycin, and/or tetracycline resistant. In the absence of sebum, the MIC(90)s/minimum bactericidal concentrations (MBC(90)s) for NB-003, NB-003 gel, salicylic acid (SA), and benzoyl peroxide (BPO) were 0.5/2.0, 1.0/2.0, 1,000/2,000, and 50/200 μg/ml, respectively. In the presence of 50% sebum, the MIC(90)s/MBC(90)s of NB003 and BPOs increased to 128/1,024 and 400/1,600 μg/ml, respectively. The MIC(90)s/MBC(90)s of SA were not significantly impacted by the presence of sebum. A reduction in the MBC(90)s for NB-003 and BPO was observed when 2% SA or 0.5% BPO was integrated into the formulation, resulting in MIC(90)s/MBC(90)s of 128/256 μg/ml for NB003 and 214/428 μg/ml for BPO. The addition of EDTA enhanced the in vitro efficacy of 0.5% NB-003 in the presence or absence of 25% sebum. The addition of 5 mM EDTA to each well of the microtiter plate resulted in a >16- and >256-fold decrease in MIC(90) and MBC(90), yielding a more potent MIC(90)/MBC(90) of ≤1/<1 μg/ml. The kinetics of bactericidal activity of NB-003 against P. acnes were compared to those of a commercially available product of BPO. Electron micrographs of P. acnes treated with NB-003 showed complete disruption of bacteria. Assessment of spontaneous resistance of P. acnes revealed no stably resistant mutant strains.

PubMed Disclaimer

Figures

Fig. 1.
Fig. 1.
The impact of NB-003 on the viability of P. acnes PAC-001. Time course of P. acnes in broth treated with 20 μg/ml NB-003. The lower limit of detection was 10 CFU, because a 1:10 dilution was necessary to neutralize the antibacterial carryover.
Fig. 2.
Fig. 2.
The impact of NB-003 and BPO on the viability of P. acnes PAC-008, a clinical isolate resistant to tetracycline, erythromycin, and clindamycin. Log reduction in P. acnes on pig skin surface treated with 0.001% to 0.25% NB-003 and 5% to 2.5% BPO.
Fig. 3.
Fig. 3.
Scanning electron micrographs of P. acnes PAC-001 before (A) and after (B) 1 h of treatment with 20 μg/ml NB-003.
See this image and copyright information in PMC

References

    1. Bogdanovich T., Ednie L. M., Shapiro S., Appelbaum P. C. 2005. Antistaphylococcal activity of ceftobiprole, a new broad-spectrum cephalosporin. Antimicrob. Agents Chemother. 49:4210–4219 - PMC - PubMed
    1. Boivin G., Goyette N., Sutcliffe J. 2008. A novel nanoemulsion active against acyclovir (ACV)- and foscarnet (FOS)-resistant herpes simplex virus (HSV) 1 and 2. Abstr. 48th Intersci. Conf. Antimicrob. Agents Chemother., abstr. V-3538
    1. Bonapace C. R., Bosso J. A., Friedrich L. V., White R. L. 2002. Comparison of methods of interpretation of checkerboard synergy testing. Diagn. Microbiol. Infect. Dis. 44:363–366 - PubMed
    1. Bowe W. P., Shalita A. R. 2008. Effective over-the-counter acne treatments. Semin. Cutan. Med. Surg. 27:170–176 - PubMed
    1. Ciotti S., Eisma R., Ma L., Baker J. R., Jr 2008. Novel nanoemulsion NB-001 permeates skin by the follicular route. Abstr. 48th Intersci. Conf. Antimicrob. Agents Chemother., abstr. A-1898

MeSH terms