The aim of this study was to evaluate the occurrence of yeasts, pseudomonads and enteric bacteria in the oral cavity of patients undergoing radiotherapy (RT) for treatment of head and neck cancer. Fifty patients receiving RT were examined before, during and 30 days after RT. Saliva, mucosa, and biofilm samples were collected and microorganisms were detected by culture and polymerase chain reaction (PCR). The most prevalent yeasts in patients submitted to RT were Candida albicans, C. tropicalis, C. krusei, C. glabrata and C. parapsilosis. Citrobacter, Enterobacter, Enterococcus, Klebsiella, Proteus, and Pseudomonas were the most frequently cultivated bacteria. Before RT, targeted bacteria were cultivated from 22.2% of edentulous patients and 16.6% of dentate patients; 30 days after RT, these microorganisms were recovered from 77.8% edentulous and 46.8% dentate patients. By PCR, these microorganisms were detected from all edentulous patients, 78.1% of dentate patients. The presence of Gram-negative enteric roads and fungi was particularly frequent in patients presenting mucositis level III or IV. Modifications in the oral environment due to RT treatment seem to facilitate the colonization of oral cavity by members of family Enterobacteriaceae, genera Enterococcus and Candida.

Abstratc: Bovine periodontitis is a progressive purulent infectious process associated with the presence of strictly and facultative anaerobic subgingival biofilm and epidemiologically related to soil management in large geographic areas of Brazil. This study aimed to detect species of the genera Porphyromonas and Prevotella, which occurr in periodontal pockets of cattle with lesions deeper than 5mm (n=26) and in gingival sulcus of animals considered periodontally healthy (n=25). Presence of the microorganisms was evaluated by independent-culture medium diagnostic method, using polymerase chain reaction (PCR) with specific primers of Porphyromonas asaccharolytica, P. endodontalis, P. gingivalis, P. gulae, Prevotella buccae, P. intermedia, P. loescheii, P. melaninogenica, P. nigrescens, P. oralis and P. tannerae. The species P. endodontalis (80.7%), P. melaninogenica (73.1%) and P. intermedia (61.5%) were the most predominant in samples of cattle with periodontitis. Regarding non-injured gingival sulcus of cattle, P. endodontalis (40%) and P. loeschei (40%) prevailed. Porphyromonas gingivalis, P. gulae and Prevotella tannerae were not detected in the 51 samples studied. Data evaluation by T test, enabled to verify that ocorrence of Porphyromonas asaccharolytica (p=0.000003), P. endodontalis (p=0.0023), Prevotella buccae (p=0.0017), P. intermedia (p=0.0020), P. melaninogenica (p=0.00006) and P. oralis (p=0.0028) is correlated with bovine periodontitis.

RESUMO.-[Treponema denticola na microbiota da periodontite bovina.] A periodontite bovina é um processo infeccioso purulento e progressivo associado à presença de biofilme subgengival anaeróbio estrito e epidemiologicamente relacionada ao manejo do solo em amplas áreas geográficas do Brasil. O trabalho teve por objetivo detectar espécies de Treponema presentes na bolsa periodontal de bovinos com lesões de profundidade maior que 5mm e do sulco gengival de animais com idade de 6 a 24 meses e considerados periodontalmente sadios. Os materiais foram colhidos por meio de cones de papel, após a remoção do biofilme supragengival, e mantidos sob congelamento (-80°C) até a extração do DNA e realização da reação em cadeia da polimerase (PCR) com o emprego de iniciadores de T. amylovorum, T. denticola, T. maltophilum, T. medium e T. vincentii. Na bolsa periodontal de 73% (19/26) dos animais foi possível detectar diretamente, pela PCR, a presença de Treponema amylovorum, de 42,3% (11/26) T. denticola e de 54% (14/26) T. maltophilum. Dos 25 sítios sadios, em 18 (72%) foi possível identificar T. amylovorum, em dois (8%) T. denticola e em oito (32%) T. maltophilum. Treponema medium e T. vincentii não foram detectados nas 51 amostras avaliadas. A presença de Treponema amylovorum, T. maltophilum na microbiota subgengival, e em especial do amplamente reconhecido periodontopatógeno T. denticola, Treponema denticola in microflora of bovine periodontitis Periodontitis in cattle is an infectious purulent progressive disease associated with strict anaerobic subgingival biofilm and is epidemiologically related to soil management at several locations of Brazil. This study aimed to detect Treponema species in periodontal pockets of cattle with lesions deeper than 5mm in the gingival sulcus of 6 to 24-month-old animals considered periodontally healthy. We used paper cones to collect the materials, after removal of supragingival plaques, and kept frozen (at -80°C) up to DNA extraction and polymerase chain reaction (PCR) using T. amylovorum, T. denticola, T. maltophilum, T. medium and T. vincentii primers. In periodontal pocket, it was possible to identify by PCR directly, the presence of Treponema amylovorum in 73% of animals (19/26), T. denticola in 42.3% (11/26) and T. maltophilum in 54% (14/26). Among the 25 healthy sites, it was possible to identify T. amylovorum in 18 (72%), T. denticola in two (8%) and T. maltophilum in eight (32%). Treponema medium and T. vincentii were not detected over all 51 evaluated samples. The presence of Treponema amylovorum, T. maltophilum and, in particular, the widely recognized T. denticola in subgingival microflora brings an original and potencially important contribution in studies of the bovine periodontitis.INDEX TERMS: Bovine periodontitis, periodontal disease, subgingival microflora, Treponema denticola.

The aim of this study was to evaluate the influence of chlorhexidine gluconate, sodium fluoride and sodium iodine on mutans streptococci counts in saliva of irradiated patients. Material and Methods: Forty-five patients were separated into three experimental groups and received chlorhexidine (0.12%), sodium fluoride (0.5%) or sodium iodine (2%), which were used daily during radiotherapy and for 6 months after the conclusion of the treatment. In addition, a fourth group, composed by 15 additional oncologic patients, who did not receive the mouthwash or initial dental treatment, constituted the control group. Clinical evaluations were performed in the first visit to dental clinic, after initial dental treatment, immediately before radiotherapy, after radiotherapy and 30, 60, 90 days and 6 months after the conclusion of radiotherapy. After clinical examinations, samples of saliva were inoculated on SB20 selective agar and incubated under anaerobiosis, at 37°C for 48 h. Total mutans streptococci counts were also evaluated by using real-time PCR, through TaqMan system, with specific primers and probes for S. mutans and S. sobrinus. Results: All preventive protocols were able to reduce significantly mutans streptococci counts, but chlorhexidine gluconate was the most effective, and induced a significant amelioration of radiotherapy side effects, such as mucositis and candidosis. Conclusion: These results highlights the importance of the initial dental treatment for patients who will be subjected to radiotherapy for head and neck cancer treatment.

Endodontic infections are mixed aerobic-anaerobic infections and several microbial groups associated to these pathologies are also involved in orofacial infections. The goal of this study was to evaluate the susceptibility of microorganisms isolated from endodontic infections to β-lactams and metronidazole and verify the production of β-lactamases. Clinical specimens were collected from 58 endodontic infections of 52 patients. The microorganisms were isolated in selective and non-selective culture media, under anaerobiosis and aerobiosis, and identified using biochemical methods. In the susceptibility tests, it was used an agar dilution method, and Wilkins-Chalgren agar enriched with blood, hemin and menadione for the anaerobes, while Mueller- Hinton agar was employed for the facultative anaerobes. The production of β-lactamases was evaluated through the biological and chromogenic cephalosporin methods. All tested isolates were sensitive to imipenem and 99.3% to amoxicillin/clavulanate association, while 16.1% showed resistance to amoxicillin and penicillin G, and 4.89% to cefoxitin. Resistance to metronidazole was just found in facultative anaerobes. Production of β-lactamases was detected in 18.2% of the isolates and presented a correlation with resistance to β-lactams.