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ABSTRACT: A medium (Brain Heart Infusion plus 10% human plasma) was developed, tested, and validated for growing Staphylococcus aureus biofilm in vitro. With this medium, S. aureus forms reproducible and robust biofilms in flow chambers under controlled shear flow and with increased viability recovery in static well plates.
Journal of microbiological methods 04/2012; 90(2):115-8. · 2.43 Impact Factor
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ABSTRACT: In Actinomyces oris T14V, sortase SrtC1 mediates the assembly of type 1 fimbriae. We analyzed the effects of the conserved residues (H184, H204, F213, Y236, L263, T265, C266 and R275) on the SrtC1 activity by site-directed mutagenesis. We identified three essential conserved residues (H204, Y236 and C266) that are critical for the assembly of type 1 fimbriae in this organism. rapid amplification of cDNA ends analyses and reverse transcriptase-PCR results indicate that srtC1 was transcribed together with the putative adhesin gene fimQ and major structural subunit gene fimP as a single polycistronic mRNA.
FEMS Microbiology Letters 06/2011; 322(2):115-22. · 2.04 Impact Factor
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ABSTRACT: Anti-microbial peptides perform many functions in the oral cavity. They may provide protection against microbial pathogens, assist in oral biofilm control, and function as an important part of the innate immune system in response to local and systemic infection. Synthetic versions of these peptides may be useful to supplement natural anti-microbial peptides or as therapeutic agents.
Journal of the California Dental Association 11/2009; 37(11):779-88.
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ABSTRACT: The effects of various antimicrobial peptides (AMPs) on disrupting the hemagglutinating ability of cellular components of the putative oral pathogen Porphyromonas gingivalis were examined. AMP inhibition of P. gingivalis 381-induced hemagglutination using vesicles (VES) or outer membrane (OM) preparations was determined within standardized hemagglutination assays using various mammalian erythrocytes. A synthetic decapeptide (KSL-W) and its truncated peptide analogs were evaluated and compared with selected classes of AMPs derived from naturally occurring innate defense peptides. All tested AMPs were effective in disrupting P. gingivalis-induced hemagglutination among tested erythrocytes, with the exception of magainin I and the truncated KSL-W analogs. LL-37 was generally the most potent followed by histatin 5. The synthetic decapeptide (KSL-W) was found to be similar to the histatin 8 peptide in terms of inhibitory effect. In addition, co-application assays (with selected oral-related AMPs+/-KSL-W) were employed to determine if co-application procedures would improve hemagglutination abrogation above that of oral-related AMPs alone. These experiments revealed that the KSL-W peptide improved hemagglutination inhibition above that of each of the oral-related peptides (histatin 5 and 8, LL-37) alone. Among mammalian erythrocytes, significant peptide-induced hemagglutination was observed for the cathelicidin class AMPs, LL-37 and indolicidin (>or=25 and >or=100 microM respectively). In contrast, KSL-W did not induce erythrocyte agglutination throughout any concentration range tested (0.1-1000 microM). Our results suggest that several AMPs are effective in disrupting P. gingivalis 381-induced hemagglutination and that the co-application of a small, synthetically derived peptide may serve to augment the role of local host AMPs engaged in innate defense.
Peptides 09/2009; 30(12):2161-7. · 2.43 Impact Factor
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ABSTRACT: The type 1 fimbriae of Actinomyces naeslundii T14V mediate adhesion of this gram-positive species to the tooth surface. The present findings show that the locus for type 1 fimbria production in this strain includes three genes, fimQ for a minor fimbrial subunit that appears to be an adhesin, fimP for the major structural subunit, and srtC1 for a type 1 fimbria-specific sortase involved in the assembly of these structures.
Infection and Immunity 09/2007; 75(8):4181-5. · 4.16 Impact Factor
