nitrocefin and Periapical-Periodontitis

The aim of the present study was to investigate the microbial flora of root filled teeth with apical periodontitis and to determine the prevalence of β-lactamase producing strains in isolated bacteria in Latvian patients.. 33 root filled teeth with asymptomatic persisting periapical lesions were selected for the present study. During nonsurgical endodontic retreatment, the root filling material was removed and canals were sampled. Determination of microbial species was based on series of biochemical tests using identification kits. All strains of bacteria were tested for β-lactamase production by using chromogenic nitrocefin-impregnated slides.. Bacteria were found in 32 (97%) of initial specimens from the teeth. The number of isolated microbial strains in the specimens ranged from one to six (mean 2.7). 79% of the isolated microbial species were Gram-positive bacteria. The most common isolates were Streptococcus (27%), Actinomyces (27%), Staphylococcus (18%), Enterococcus (18%) and Lactobacillus (18%) spp. Yeasts were found as four isolates in 3 cases (9%). β-lactamase-producing bacterial strains were detected in 12 specimens, 36% of the patients. The most common enzyme-producing bacteria belonged to Actinomyces and Staphylococcus spp.. The microbial flora in previously treated root canals with apical periodontitis is limited to a small number of predominantly Gram-positive microbial species. The most common isolates are Streptococcus, Actinomyces, Staphylococcus, Enterococcus and Lactobacillus spp. A moderately high prevalence of β-lactamase producing bacterial strains was detected in patients with root filled teeth with apical periodontitis.

Topics: Actinomyces; Bacillus; Bacteriological Techniques; beta-Lactamases; Candida albicans; Cephalosporins; Chromogenic Compounds; Dental Pulp Cavity; Enterococcus; Gram-Positive Bacteria; Humans; Indicators and Reagents; Lactobacillus; Latvia; Periapical Periodontitis; Retreatment; Root Canal Therapy; Staphylococcus; Streptococcus; Tooth, Nonvital

Samples were taken under strictly anaerobic conditions from the root canals of 22 patients having a tooth in which necrotic pulp was associated with an inflammatory peri-apical lesion an optical periodontitis. In the majority of cases (85%), these lesions were chronic and the pulp chamber was closed. One hundred and two strains were isolated, 71.7% of the bacteria being obligate anaerobes and 49.8% being Gram-negative bacilli. Their ability to produce beta-lactamases was tested and 8.8% gave a positive reaction in a cefinase test. These cefinase positive strains were nevertheless susceptible to 3rd-generation cephalosporins (cefoxitin) and to amoxicillin-clavulanate, with the exception of M. Morganii.

Topics: Actinomyces; Amoxicillin-Potassium Clavulanate Combination; Anti-Bacterial Agents; Bacteriological Techniques; Bacteroides; beta-Lactam Resistance; beta-Lactamases; Cefoxitin; Cephalosporins; Dental Pulp Cavity; Dental Pulp Necrosis; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Indicators and Reagents; Peptostreptococcus; Periapical Periodontitis; Prevotella; Streptococcus