Identification of microorganisms isolated from saliva, crown and root canal of teeth with endodontic failure and antimicrobial suscetibility of Enterococcus faecalis

Orientador: Brenda Paula Figueiredo de Almeida GomesDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: O objetivo deste trabalho foi identificar Enterococcus spp., Staphylococcus spp., Candida spp. e enterobactérias na saliva e a microbiota do material restaurador e dos canais radiculares de 30 pacientes que apresentavam algum dente com insucesso endodôntico e estudar a suscetibilidade antimicrobiana das cepas de E. faecalis isoladas dos canais radiculares destes pacientes. A metodologia utilizou meio de transporte, cultura e incubação que propiciaram o crescimento de bactérias anaeróbias estritas e facultativas e diversos meios seletivos para isolamento de Enterococcus spp., enterobactérias, leveduras e fungos. Do total de 114 espécies bacterianas isoladas nos canais radiculares, 81,5% eram bactérias anaeróbias facultativas, 18,5% anaeróbias estritas, 86% Gram-positivas e 14% Gramnegativas. Os gêneros bacterianos isolados dos canais radiculares foram: Staphylococcus (15/50%), Streptococcus (11/36,7%), Actinomyces (12/40%), Enterococcus, Gemella (8/26,7%), Propionibacterium, Clostridium (4/13,3%), Peptostreptococcus, Bifidobacterium, Eubacterium (3/10%), Lactobacillus, Prevotella (2/6,7%), Candida (1/3,3%). Enterococcus spp., Staphylococcus spp., Candida spp. e enterobactérias foram isolados em 26,7%, 50%, 3,3% e 16,7% dos canais radiculares, em 20%, 40%, 6,7 % e 13,3% das coroas e em 43,3%, 56,7%, 50% e 26,7% da saliva, respectivamente. As cepas de E. faecalis isoladas (8/30) foram testadas através do método E-test, sendo 100% suscetíveis à amoxicilina + ácido clavulânico e à gentarnicina, 87,5% suscetíveis, à amoxicilina e moxifloxacina e 60% à ciprofloxacina. Entretanto, 100% das cepas foram resistentes à clindamicina e metronidazol, 87,5% à azitromicina e rifampicina. Concluí-se que a microbiota de dentes com insucesso endodôntico é composta principalmente por bactérias anaeróbias facultativas, predominantemente Gram-positivas. Os gêneros Staphylococcus spp., Streptococcus spp., Actinomyces spp. e E. faecalis foram os mais prevalentes em canais radiculares. Enterococcus spp., Staphylococcus spp., Candida spp. e enterobactérias foram identificados na saliva, na coroa e nos canais radiculares. Os antimicrobianos mais efetivos contra E. faecalis foram amoxicilina + ácido clavulânico e gentarnicinaAbstract: The aim of this study was to identify Enterococcus spp., Staphylococcus spp., Candida spp. and enterobacteria in the saliva, to identify microorganisms in the restorative material of the crown and in the root canal of 30 failed endodontically treated teeth with periradicular lesion and to test antibiotic susceptibility of E. faecalis isolates from obtured root canal. The transport media, specific culture media and adequated gaseous requirement were used to isolate as many as strict and facultative anaerobes as possible. Seleted media were used to isolate Enterococcus spp., enterobacteria and yeasts. From the 114 microorganisms isolated from the root canais, 81.5% were facultative anaerobes and 18.5% strict anaerobes, 86% were Gram-positive and 14% Gram-negative microorganisms. The most frequently bacterial genera recovered from the root canais were: Staphylococcus (15/50%), Streptococcus (11/36.7%), Actinomyces (12/40%), Enterococcus, Gemella (8/26.7%), Propionibacterium, Clostridium (4/13.3%), Peptostreptococcus, Bifidobacterium,Eubacterium (3/10%), Lactobacillus, Prevotella (2/6.7%) and Candida (1/3,3%). Enterococcus spp., Staphylococcus spp., Candida spp. and enterobacteria were isolated in 26.7%, 50%, 3.3% and 16.7% of the canaIs, in 20%, 40%, 6.7 % e 13.3% of the crown and in 43.3%, 56.7%, 50% and 26.7% of saliva, respectively. Antibiotic sensivity of Enterococcus faecalis isolates (8/30) were tested for their susceptibility/resistance and it was accomplished with the E-testSystem. Enterococcus faecalis were 100% susceptible,to amoxicilin combined with clavulanate, gentamicin, 87.5% to amoxicilin and moxifloxa~in and 60% to ciprofloxacin. However, 100% of the E. faecalis isolates were resistant .to clindamycin and to metronidazol, 87.5% to azithromycin and rifanpicin. It was concluded that root canais with failed endodontic therapy comprise predominantly facultative anaerobic Gram-positive microorganisms. Moreover, Enterococcus spp., Staphylococcus spp., Candida spp. and enterobacteria could also be detected in the saliva and in the root canaIs. The effective antibiofics for E. faecalis were amoxicilin combined with clavulanate and gentamicinMestradoEndodontiaMestre em Clínica Odontológic