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ESCHERICHIA COLI STRAINS PRODUCING STREPTOCOCCUS MUTANS PROTEINS RESPONSIBLE FOR COLONIZATION AND VIRULENCE *
Author(s) -
Curtiss Roy,
Holt Robert G.,
Barletta Raúl G.,
Robeson James P.,
Saito Shigeno
Publication year - 1983
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.1983.tb26908.x
Subject(s) - clinical microbiology , library science , microbiology and biotechnology , streptococcus mutans , biology , bacteria , genetics , computer science
Streptococcus mutans is a principal etiologic agent of dental caries and is likely one of the most ubiquitous bacterial infectious disease agents worldwide.'-3 The ability of s. mutans to colonize the oral cavity is due to sucroseindependent and sucrose-dependent adherence to the pellicle-coated tooth surface with glucan facilitated aggregation between cells to result in plaque. Cariogenicity is then caused by the ability of S. mutans in plaque to metabolize free sugars and both extra and intracellular complex carbohydrates to yield predominantly lactic acid.'-3 The S. mutans gene products that contribute to colonizing ability and thus virulence include glucosyltransferases, glucanbinding proteins, and a diversity of less well-characterized cell-surface proteins and carbohydrate antigens that may also promote adherence or aggregation. Until recently, S. mutans was unable to be analyzed genetically by classical methods of mutagenesis and gene transfer for mapping and complementation. We thus chose to use gene cloning technologies to introduce S. mutans genes into suitable strains of Escherichia coli K-12. S. mutans plasmid' and c h r o m ~ s o m a l ~ ~ genes are expressed very well in E. coli. For example, the S. mutans gene for aspartic acid semialdehyde dehydrogenase possesses a very unique promoter sequence region that results in 7% of the total E. coli protein being the product of this one S. mutans Furthermore, S. mutans gene products can substitute for E. coli gene products that are missing because of the presence of gene mutations or deletions in the E. coli recipient strain.'.' In that regard, Perry and Kuramitsu' have developed a method for transformation of S. mutans strain GS-5 (serotype c], making it possible to mutate S. mutans genes cloned in E. coli, to return them to S. mutans and then to examine the effect of a known mutation altering a well-characterized gene product on S. mutans virulence. Similarly, we have been able to use antibodies against S. mutans gene products made by