A method for the identification of Streptococcus mutans in gingival margin plaque by immunofluorescence.
A method was developed to identify Streptococcus mutans in natural dental plaque by indirect immunofluorescence staining, using a high-titred polyclonal antiserum raised against a serotype c strain of S. mutans followed by an FITC conjugate. Specificity was determined by staining 45 representative strains of plaque organisms, which demonstrated minimal cross-reactions. In vitro incubation of S. mutans NCTC 10449 films with a human serum containing antibodies to S. mutans and the presence of extracellular polysaccharide did not inhibit staining. The staining method enabled 98% of the streptococci to be detected in mixtures of S. mutans NCTC 10449 and Lactobacillus casei NCTC 10302. S. mutans was detected at a ratio of 1:100,000 in mixtures of pure cultures. In plaque samples, S. mutans could be distinguished from other organisms, including an unidentified cross-reacting bacillus found in some gingival plaque samples. The results suggest that immunofluorescence is a fast, practical method for identifying specific bacteria in plaque and, therefore, could be of use in microbiological studies of caries.
Bush
M S
MS
Reta Lila Weston Institute of Neurological Studies, University College and Middlesex Hospital Medical School, London, UK.
Challacombe
S J
SJ
Newman
H N
HN
D000818:Animals; D003429:Cross Reactions; D003773:Dental Plaque / Q000382:microbiology*; D005455:Fluorescent Antibody Technique; D005881:Gingiva / Q000382:microbiology; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D013194:Staining and Labeling; D013295:Streptococcus mutans / Q000302:isolation & purification*