Aims: To isolate bacteriophages lytic for oral pathogens from human saliva, dental plaque and mature biofilms constituted from saliva-derived bacteria.
Methods and results: Saliva and dental plaque samples from healthy volunteers and from patients with gingivitis and periodontitis were examined for the presence of lytic bacteriophage using a panel of oral pathogens and bacteria isolated from the samples. Samples were also enriched for bacteriophage using static culture techniques and mature biofilms. A limited number of samples contained bacteriophage particles that were visualized using electron microscopy. Cultures yielded phage infecting non-oral bacteria (Proteus mirabilis) but no bacteriophage specific for recognized oral pathogens were found. Some micro-organisms from the oral microflora elaborated antibacterial substances that inhibited growth of other residents of the oral cavity.
Conclusions: Unlike other ecosystems, the composition of the oral cavity does not appear to be heavily influenced by interactions between bacteriophages and their hosts.
Significance and impact of the study: Bacteriophage for control of oral infections may need to be obtained from other sources. Antibacterial substances derived from some members of the oral microflora warrant investigation as potential antibiotics.