Int J Oral Biol.  2014 Mar;39(1):9-13.

Incidence of Tetracycline Resistance Genes, tet(M) and tet(O), in Streptococci Isolated from Dental Plaques of Koreans

• Kim YH
• Lee SY

Abstract

Streptococci are among the normal human microflora that populate the oral cavity. However, oral streptococci are known as a major causative agent for dental caries and bacterial endocarditis. Tetracycline is a broad-spectrum antibiotic that is used for oral infections but two mechanisms of tetracycline resistance in streptococci have been reported. The tet(K) and tet(L) genes in these bacteria are related to the active efflux of tetracycline, whereas tet(M) and tet(O) confer ribosomal protection from this antibiotic. It has been reported that the tetracycline resistance of streptococci is related mainly to the activity of tet(M) and tet(O). In our present study, we examined the prevalence of tet(M) and tet(O) in oral streptococci isolated from Korean dental plaques using PCR. One hundred and forty eight of 635 isolates (23.3%) were tetracycline resistant; 68 of these strains (46%) harbored tet(M) and 3 strains (2%) were positive for tet(O). However, tet(M) and tet(O) did not co-exist in any of the resistant strains. Seventy seven of the 148 tetracycline resistant strains (52%) were negative for both the tet(M) and tet(O) genes.

Keyword

tetracycline; resistance; streptococci

MeSH Terms

Bacteria
Dental Caries
Endocarditis, Bacterial
Humans
Incidence*
Mouth
Polymerase Chain Reaction
Prevalence
Tetracycline
Tetracycline Resistance*
Tetracycline