The effect of lactoferrin on oral bacterial attachment.
BACKGROUND
Lactoferrin (Lf), an iron-binding salivary glycoprotein, plays an important role in human innate defense against local mucosal infection. We hypothesized that Lf interferes with initial oral bacterial attachment to surfaces by iron sequestration, so inhibiting subsequent biofilm formation. The objective was to investigate the effect of Lf on the early stages of single-species and multi-species oral biofilm development.


METHODS
Streptococcus gordonii, Streptococcus mutans, Fusobacterium nucleatum and Porphyromonas gingivalis were used in this study. Glass disks of a two-track flow cell coated with flowing artificial saliva (0.3 ml/min) with and without Lf (100 microg/ml) were used for studying bacterial attachment (3 h, 37 degrees C). Attachment was also examined by incubating single or multiple species of test bacteria (10(7) colony-forming units/ml) with Lf-coated (20-100 microg/ml) and uncoated glass slides. The effects of beta-lactoglobulin, 2,2'-dipyridyl (25-100 microg/ml), an iron chelator, and FeCl3 on attachment were also examined.


RESULTS
Lf inhibited the initial attachment of S. gordonii (50.3%, P < 0.05) but not that of F. nucleatum and P. gingivalis. However, the attachment of a dual-species biofilm containing S. gordonii (i.e. S. gordonii/F. nucleatum or S. gordonii/P. gingivalis) was significantly reduced (48.7% or 62.1%, respectively, P < 0.05) in the presence of Lf. beta-Lactoglobulin did not affect the attachment of S. gordonii. In the presence of 100 microm 2,2'-dipyridyl, attachment of S. gordonii was reduced by 53.87%. No reduction in attachment was noted in S. gordonii pretreated with Lf (100 microg/ml) and FeCl3 (20-200 microm).


CONCLUSIONS
Lf suppresses initial attachment of S. gordonii and S. gordonii coaggregates by iron sequestration. This may lead to subsequent inhibition of oral biofilm development.
Arslan
S Y
SY
Department of Pediatric Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL 60612-7212, USA.
Leung
K P
KP
Wu
C D
CD
D015082:2,2'-Dipyridyl / Q000494:pharmacology; D001422:Bacterial Adhesion / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects; D002712:Chlorides; D015169:Colony Count, Microbial; D005290:Ferric Compounds / Q000494:pharmacology; D016967:Fusobacterium nucleatum / Q000187:drug effects* / Q000254:growth & development; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007502:Iron Chelating Agents / Q000494:pharmacology; D007781:Lactoferrin / Q000008:administration & dosage / Q000494:pharmacology*; D007782:Lactoglobulins / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009055:Mouth / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000187:drug effects* / Q000254:growth & development; D012464:Saliva, Artificial / Q000494:pharmacology; D012471:Salivary Proteins and Peptides / Q000008:administration & dosage / Q000494:pharmacology; D013291:Streptococcus / Q000187:drug effects* / Q000254:growth & development; D054773:Streptococcus gordonii / Q000187:drug effects / Q000254:growth & development; D013295:Streptococcus mutans / Q000187:drug effects / Q000254:growth & development
D002712:Chlorides; D005290:Ferric Compounds; D007502:Iron Chelating Agents; D007782:Lactoglobulins; D012464:Saliva, Artificial; D012471:Salivary Proteins and Peptides; D015082:2,2'-Dipyridyl; D007781:Lactoferrin; C024555:ferric chloride