Abstract

CARDENAS IL, Testa M. Estudio de la sensibilidad a los antimicrobianos de patógenos periodontales. Acta odontol. venez [online]. 2008, vol.46, n.3, pp.273-277. ISSN 0001-6365.

Taking into account that several failures in antibiotic treatments used in periodontitis are driving to the appearance of resistant strains, the aim of this work was to realize a preliminary study of the resistance pattern to commonly used antimicrobials of regional Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum strains. Antibiotic susceptibility test was performed by NCCLS (National Committee for Clinical Laboratory Standards) agar dilution method. Proof antibiotics were selected among the most used in the clinical practice in our region: amoxicillin, clindamycin, doxycycline, erythromycin, metronidazole and tetracycline. The results showed that 100% of P.gingivalis strains were resistant to metronidazole and susceptible to tetracycline, and 33% susceptible to clindamycin. The MICs obtained for amoxicillin were between 1 and 32 mg/ml, for doxycycline between 0,125 and 5 mg/ml and for erythromycin between 8 and >32 mg/ml. In the case of P. intermedia, were also observed a 100% of resistance to metronidazole, 67% of susceptibility to tetracycline, and 62,5 % of susceptibility to clindamycin.. The MICs for amoxicillin were between 0,125 y 16 mg/ml, for doxycycline between 0,125 and 4 mg/ml, and for erythromycin between 8 and >32 mg/ml. 100% of F. nucleatum strains were susceptible to tetracycline and resistant to metronidazole, and a 25% susceptible to clindamycin. MICs to amoxicillin were between 0,125 y 16 mg/ml, for doxycycline between 0,125 and 4 mg/ml, and to erythromycin between 16 and >32 mg/ml. Resistance patterns obtained with strains of our region showed higher percentages of resistance than those reported by other authors, which might owe to the lack of control politicise for the use of antimicrobials in our country. However, MICs values founded for the 50 and 90% of strains are similar to tose reported by NCCLS, except in the case of doxycycline, where our MICs are lower, and for erythromycin that are higher with P. gingivalis.

Keywords : antibiotics; periodontal pathogens; antibiotic susceptibility tests.