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Utilization of relevant nutritional resources by root canal isolates
Author(s) -
Khot A.,
Spratt D.,
Ng Y.L.,
Gulabivala K.
Publication year - 2004
Publication title -
international endodontic journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.988
H-Index - 119
eISSN - 1365-2591
pISSN - 0143-2885
DOI - 10.1111/j.1365-2591.2004.834-2.x
Subject(s) - brain heart infusion , bacterial growth , serial dilution , microbiology and biotechnology , biology , bacteria , streptococcus mitis , saliva , actinomyces , food science , streptococcus , biochemistry , medicine , genetics , alternative medicine , pathology , agar
Aim To identify nutritional sources potentially available within the root canal systems that may allow the growth of bacteria. Methodology All the cultivable bacterial species ( Aerococcus viridans, Actinomyces viscosus, Rothia dentocariosa, Streptococcus mitis, Corynebacterium durum, Pediococcus urinaeequi, Campylobacter gracilis, Fusobacterium nucleatum and Prevotella corporis ) from a single tooth infection were used. The nutrient sources tested included those potentially available from teeth (enamel, dentine, cementum, pulp tissue, saliva, serum and blood), artificial media (reduced transport fluid (RTF), brain heart infusion (BHI) and nutrient broth) and a control (phosphate‐buffered saline (PBS)). Each medium was inoculated with each of the bacterial isolates in microtitre plates in doubling dilution series. All experiments were carried out in triplicate. The plates were incubated either aerobically or anaerobically, as appropriate. Bacterial growth was assessed as a function of relative optical densities (ODs) at different nutrient dilutions measured by spectrophotometry at 24 and 48 h. Mean values were calculated ( n = 3) and the resultant data were analysed to determine the presence or absence of growth. Results The effectiveness of artificial media in supporting the growth of the isolates was confirmed; BHI supported the growth of all isolates, but nutrient broth supported the growth of only six strains. As expected, PBS and RTF did not support bacterial growth. Of the dental tissues, enamel and dentine did not support bacterial growth, but cementum supported the growth of C. durum and C. gracilis. Pulp tissue only supported the growth of A. viscosus and C. gracilis. The body fluids supported bacterial growth well. Blood supported growth of all bacterial isolates except C. gracilis. Serum supported the growth of all isolates except P. urinaeequi and C. gracilis. Saliva supported the growth of A. viridans, A. viscosus, R. dentocariosa, C. durum and P. urinaeequi. Conclusions The differential support of growth by the nutrient sources revealed in the present study support the conclusion that during root canal infection, the causative bacteria may derive nutrition from a variety of locally abundant key tissues, but the principal components of hard and soft tissue present within teeth support bacterial growth only to a limited extent or does not support at all. The principal requirements are body fluids.