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.
Reta Lila Weston Institute of Neurological Studies, University College and Middlesex Hospital Medical School, London, UK.
M S
MS
Bush
S J
SJ
Challacombe
H N
HN
Newman
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*