IN-VITRO SUSCEPTIBILITY, TOLERANCE AND GLYCOCALYX PRODUCTION IN STREPTOCOCCUS-MUTANS

We studied the presence of high-level resistance to aminoglycosides, p enicillin tolerance and glycocalyx production in 160 isolates of Strep tococcus mutans. Susceptibility to amoxycillin, cefazolin, imipenem, e rythromycin, clindamycin, vancomycin and teicoplanin was also investig ated. Of the isolates analysed, 58.8% produced glycocalyx in vitro and 2.5% were penicillin-tolerant. High-level resistance to streptomycin was found in 16.3% of the isolates, but all were sensitive to all othe r antibiotics tested. We found no significant relationship between gly cocalyx production and high-level streptomycin resistance, penicillin tolerance or antibiotic susceptibility, except for a greater susceptib ility to clindamycin and vancomycin in isolates that produced glycocal yx. Although our findings reflect the clinically favourable pattern of susceptibility currently found in this species, the appearance in som e isolates of resistance, tolerance and glycocalyx production should b e investigated because of the risks involved in endocarditis caused by S. mutans.