Open AccessCompositional modification of nascent in vitro dental plaques by human host‐defence peptides
Author(s) -
Madhwani Tejal,
McBain Andrew J.
Publication year - 2012
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2011.00922.x
Subject(s) - cathelicidin , microbiology and biotechnology , biology , bacteria , in vitro , beta defensin , defensin , lysozyme , antimicrobial , antimicrobial peptides , biochemistry , genetics
Salivary host‐defence peptides include defensins, histatins and cathelicidin. We have investigated the effects of these peptides on the microbial composition of dental plaques. Salivary consortia, established within hydroxyapatite disc models, were exposed during development to physiological levels of human neutrophil proteins ( HNP ) 1 and 2; human β defensins (hβ D ) 1, 2 and 3; histatins ( H is) 5 and 8; and cathelicidin ( LL 37). Effects on aggregation and microbial composition were determined using fluorescence microscopy; and differential culture with PCR ‐ DGGE , respectively. LIVE / DEAD microscopic analysis indicated that HDP s decreased total bacterial viability, whilst β defensins, paired HNP s, H is 5, H is 8 and the HDP s combined inhibited bacterial aggregation. According to differential culture, all test HDP s (except H is 5) significantly decreased the abundance of G ram‐negative anaerobes and lactobacilli (except HNP 2, hβ D 1, paired HNP s and H is 5). Combined HNP s and paired hβ D 1 and 3 inhibited streptococci, whereas HNP 1, hβ D 1, hβ D 3, H is 5 and LL 37 increased streptococcal numbers. According to cluster analyses of DGGE profiles, HDP ‐exposed plaques were compositionally distinct from undosed controls. Thus, whilst HDP s reportedly exhibit variable potency against oral bacteria in endpoint susceptibly tests, exposure of nascent plaques can markedly influence bacterial viability, composition and microbial aggregation.