ABSTRACT: Gingivitis is an infectious inflammatory process that generates local and systemic conditions, compromising the masticatory capacity of animals. Virginiamycin controls and prevents gingivitis and necrotizing gingivitis in cattle. However, the interaction and effect with different sera and salivary elements remain unknown. The present 6-month longitudinal study evaluated the hematological, metabolic, and salivary buffering capacity profiles of calves with gingivitis treated with virginiamycin. Ten calves were divided into two groups: control and virginiamycin (n = 5 each). Calves in the virginiamycin group had a lower occurrence of gingivitis (P < 0.01, Student’s t-test). The animals that developed gingivitis in both experimental groups had higher salivary levels of alkaline phosphatase (P = 0.01915) and lower serum levels of albumin (P = 0.0028). Additionally, animals receiving virginiamycin had higher serum levels of magnesium (P = 0.008), albumin (P = 0.0008), urea (P = 0.008), alkaline phosphatase (P = 0.008), total proteins (P = 0.008), and plasma protein (P = 0.018). Salivary buffering capacity was negatively correlated with salivary variables such as calcium, magnesium, albumin, total protein, and aspartate aminotransferase and serum variables such as albumin and aspartate aminotransferase. Results of the present study suggested that the occurrence of periodontopathies in episodes is reflected in the local and systemic alterations in animals. In this context, clinical periodontal monitoring also showed the benefits of virginiamycin supplementation on gingival conditions and systemic health markers, in addition to controlling the two precursor forms of periodontitis.

RESUMO: Gengivites são processos infecto-inflamatórios que geram quadros locais e sistêmicos, com comprometimento da capacidade mastigatória dos animais. A virginiamicina controla e previne a gengivite e a gengivite necrosante em bovinos; no entanto, a interação e efeito com diferentes elementos séricos e salivares permanecem desconhecidos. O presente estudo teve como objetivo avaliar, em um estudo longitudinal com duração de seis meses, os perfis hematológicos, metabólicos e de capacidade tamponante salivar de bezerros com gengivite e tratados com virginiamicina. Foram utilizados 10 bezerros divididos em dois grupos: grupo controle (n = 5) e grupo virginiamicina (n = 5). Os bezerros do grupo virginiamicina apresentaram menor ocorrência de gengivite (P < 0,01, teste T - Student). Os animais que desenvolveram gengivite, de ambos os grupos experimentais, apresentaram níveis salivares mais elevados de fosfatase alcalina (P = 0,01915) e níveis séricos menores de albumina (P = 0,0028). Observou-se também que os animais que receberam virginiamicina apresentaram níveis séricos mais elevados de magnésio (P = 0,008), albumina (P = 0,0008), ureia (P = 0,008), fosfatase alcalina (P = 0,008), proteínas totais (P = 0,008) e proteína plasmática (P = 0,018). As análises de capacidade tamponante salivar foram correlacionadas negativamente às variáveis salivares como cálcio, magnésio, albumina, proteína total e aspartato aminotransferase e às variáveis séricas como a albumina e aspartato aminotransferase. Os resultados do presente estudo sugerem que a ocorrência em episódios das periodontopatias refletem-se em alterações locais e sistêmicas nos animais. Neste contexto, o monitoramento clínico periodontal também evidenciou os benefícios do emprego de suplementação pela virginiamicina sobre as condições gengivais e marcadores sistêmicos de saúde, além do controle das duas formas precursoras de periodontites.

RESUMO: Periodontite é a resposta inflamatória de um hospedeiro suscetível causada por complexa microbiota, composta predominantemente por bactérias anaeróbias Gram-negativas. Com o objetivo de caracterizar a microbiota bacteriana subgengival associada à periodontite ovina foi realizada a reação em cadeia da polimerase (PCR) de amostras de biofilme subgengival de 14 ovinos com a enfermidade e 14 ovinos periodontalmente saudáveis, com destaque para micro-organismos Gram-negativos e Gram-positivos considerados importantes periodontopatógenos. As bactérias mais prevalentes em 14 animais com lesões periodontais foram Tannerella forsythia (78,6%), Treponema denticola (78,6%), Fusobacterium nucleatum (64,3%) e Porphyromonas gingivalis (50%). Entretanto, nos 14 ovinos sem lesões periodontais, F. nucleatum (42,8%) foi a bactéria mais detectada. Associação estatisticamente diferente foi observada para Campylobacter rectus, Enterococcus faecium, Prevotella nigrescens, T. forsythia e T. denticola (p<0,05) nos ovinos com periodontite em comparação entre os dois grupos. Aggregatibacter actinomycetemcomitans, Enterococcus faecalis e Porphyromonas gulae não foram detectados em nenhuma das amostras pesquisadas. Conclui-se que C. rectus, E. faecium, P. nigrescens, T. forsythia e T. denticola estão associados às lesões resultantes da periodontite ovina com manifestação clínica grave e F. nucleatum o micro-organismo mais prevalente no biofilme subgengival de animais periodontalmente sadios.

ABSTRACT: Periodontitis is an inflammatory response in a susceptible host caused by complex microbiota, predominantly composed of Gram-negative anaerobic bacteria. Aiming to characterize the subgingival bacterial microbiota associated with ovine periodontitis, polymerase chain reaction (PCR) was performed in subgingival periodontal pocket samples of 14 sheep with severe periodontitis and in subgingival sulcus biofilm of 14 periodontally healthy sheep in search mainly of Gram-negative and Gram-positive microorganisms considered important periodontopathogens. The most prevalent bacteria in the sheep with periodontal lesions were Tannerella forsythia (78.6%), Treponema denticola (78.6%), Fusobacterium nucleatum (64.3%), and Porphyromonas gingivalis (50%), whereas in the healthy sheep, F. nucleatum (42.8%) was the most often detected bacterium. Statistically significant differences were observed for Campylobacter rectus, Enterococcus faecium, Prevotella nigrescens, T. forsythia, and T. denticola (p<0.05) in the sheep with periodontitis in the comparison between groups. Aggregatibacter actinomycetemcomitans, Enterococcus faecalis, and Porphyromonas gulae were not detected in any of the samples analyzed. In conclusion, C. rectus, E. faecium, P. nigrescens, T. forsythia, and T. denticola were associated with severe lesions caused by ovine periodontitis, and F. nucleatum was the most prevalent microorganism in the subgengival sulcus biofilm of healthy sheep.

Abstract: Based on aroeira's (Myracrodruon urundeuva) antimicrobial activity and a future trend to compose intracanal medication, the aim of this study was to assess in vivo inflamatory tissue response to the extracts by edemogenic and histological analysis containing inactivated facultative and anaerobic microorganisms. For edema quantification, eighteen animals were divided into three groups (n = 3, periods: 3 and 6 hours) and 0.2 mL of 1% Evans blue per 100 g of body weight was injected into the penile vein under general anesthesia. After 30 min the animals received a subcutaneous injection in the dorsal region of aqueous or ethanolic extract of aroeira or saline (control) containing inactivated bacteria. Samples were collected, immersed in formamide for 72h, and evaluated by spectrophotometry (630 m). For histological analysis, polyethylene tubes with the extracts were implanted in the dorsal of 30 male rats. Analysis of the fibrous capsule and inflammatory infiltrate were performed after 7 and 30 days. The aqueous extract group induced less edema in both postoperative periods compared to the other groups, but the differences were not significant (p > 0.05). Tissue repair was significantly better after 30 days than after 7 days (p < 0.01). The aqueous solution showed less inflammatory response than the ethanolic solution (p < 0.05), with tendency for better results than control after 7 days. After 30 days, the response to both extracts was similar to control. The aqueous and ethanolic aroeira extracts containing inactivated microorganisms showed a trend for better results than saline, even when associated with microorganisms, and facilitated the tissue repair process.

Resumo: A periodontite bovina é um processo infeccioso purulento e progressivo associado à presença de biofilme subgengival anaeróbio estrito e facultativo e de incidência em extensas áreas geográficas do Brasil. O trabalho teve por objetivo detectar espécies dos gêneros Porphyromonas e Prevotella presentes na bolsa periodontal de bovinos com lesões de profundidade maior que 5mm (n=26) e do sulco gengival de animais com idade de 6 a 24 meses e considerados periodontalmente sadios (n=25). A presença dos microrganismos foi avaliada pelo método independente de cultivo bacteriano, por meio da reação em cadeia da polimerase (PCR) com iniciadores específicos para Porphyromonas asaccharolytica, P. endodontalis, P. gingivalis, P. gulae, Prevotella buccae, P. intermedia, P. loescheii, P. melalinogenica, P. nigrescens, P. oralis e P. tannerae. P. endodontalis (80,7%), P. melalinogenica (73,1%) e P. intermedia (61,5%) foram os mais prevalentes nas amostras de bovinos com periodontite. Já no sulco gengival de bovinos sem lesões prevaleceram P. endodontalis (40%) e P. loeschei (40%). Porphyromonas gingivalis, P. gulae e Prevotella tannerae não foram detectados nas 51 amostras pesquisadas. A partir da avaliação dos dados pelo teste T, verificou-se que a ocorrência de Porphyromonas asaccharolytica (p=0.000003), P. endodontalis (p=0.0023), Prevotella buccae (p=0.0017), P. intermedia (p=0.0020), P. melalinogenica (p=0.00006) e P. oralis (p=0.0028) está associada à periodontite bovina.

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.

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, traz uma contribuição original de importância potencial nos estudos da periodontite bovina

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.

The objective of this study was to evaluate the microbial susceptibility to ß-lactams and metronidazole, and evaluate the production of ß-lactamases by microorganisms isolated from patients with chronic or aggressive periodontitis. The samples were obtained from 50 patients with periodontitis and microorganisms were isolated onto selective and nonselective culture media, identified by biochemical methods and tested for susceptibility to antimicrobial agents (amoxicillin, amoxicillin/clavulanate, cefoxitin, imipenem, metronidazole, penicillin G). The isolates were resistant to at least 1 mg/ml of any drug tested were evaluated to verify the production of ß-lactamases by the method of double layer (or biological) and chromogenic cephalosporin using nitrocefin. The results evidenced resistance to amoxicillin and penicillin G, while the susceptibility to association amoxicillin/clavulanate, imipenem and cefoxitin was widely disseminated among the organisms. Resistance to these drugs showed a clear correlation with the production of ß-lactamase in the majority of microbial groups.

El objetivo fue evaluar la susceptibilidad a ß-lactámicos y metronidazol, y evaluar la producción de ß-lactamasas por microorganismos aislados de pacientes con periodontitis crónica y agresivo. Las muestras fueron obtenido de 50 pacientes con periodontitis y microorganismos aislados en medios de cultivo selectivos y no selectivos, identificados por métodos bioquímicos y probados a la susceptibilidad a los antimicrobianos (amoxicilina, amoxicilina/clavulanato, cefoxitina, imipenem, metronidazol, penicilina G). Los aislados fueron resistentes a por lo menos 1 mg/ml de cualquier drogas analizadas fueron evaluados para verificar la producción de ß-lactamasas por el método de doble capa (o biológico) y nitrocefina. Los resultados mostraron resistencia a amoxicilina y penicilina G, mientras la susceptibilidad a la asociación amoxicilina/ clavulanate, cefoxitina y imipenem fue ampliamente difundido entre los microrganismos. Resistencia a estas drogas mostraron una clara correlación con la producción de ß-lactamasas en la mayoría de grupos microbianos.

OBJECTIVES: This study evaluated subcutaneous tissue response to Aroeira (Myracrodruon urundeuva) extract employing edemogenic and histological analyses. MATERIAL AND METHODS: Test groups consisted of aqueous and ethanolic Aroeira extracts and saline (control). For edema quantification, 18 rats received an intravenous injection of Evan's Blue. After 30 min, the extracts and saline were injected on the dorsum of the rats, which were then sacrificed after 3 and 6 h. Readings were performed in a spectrophotometer. For subcutaneous implantation, 30 rats received a polyethylene tube containing the extracts on their dorsum and then they were killed after 7 and 28 days. The samples were processed for histological analysis and evaluated with a light microscope. The inflammatory infiltrate was quantified. RESULTS: There were no statistically significant differences between aqueous extract and saline groups in relation to edema quantification in the different periods (p>0.05). Ethanolic solution resulted in more edema independently of the experimental period (p<0.05). Histological analysis showed similar results on the 7-day period for the 3 groups. There was a notable reduction on inflammatory cell number for saline and aqueous extract groups at 28 days. CONCLUSION: The aqueous extract showed biocompatible properties similar to those of saline.

The extracts of plants from Brazilian savanna are currently used in popular medicine. This study evaluated the inhibitory activity of the alcoholic and aqueous extracts from savanna plants on periodontal bacteria. The minimal inhibitory concentrations were evaluated by the agar dilution method, using Wilkins-Chalgren agar. Antimicrobial activity of plants extracts on microbial biofilms was determined in microplates. Psidium cattleianum and Myracrodruon urundeuva extracts demonstrated significant inhibitory activity on all bacterial strains tested; alcoholic and aqueous extracts showed similar results. The extracts from these two species were able to inhibit both planktonic cells and microbial biofilm.

Los extractos de las plantas de la sabana brasileña actualmente se utilizan en la medicina popular. Este estudio evaluó la actividad inhibitoria de los extractos alcohólicos y acuosos de plantas de la sabana en bacterias periodontales. Las concentraciones inhibitorias mínimas fueron evaluados por el método de dilución en agar, utilizando agar Wilkins-Chalgren. La actividad antimicrobiana de los extractos de plantas en las biopelículas microbianas se determinó en microplacas. Los extractos de Psidium cattleianum y Myracrodruon urundeuva demostraron una importante actividad inhibitoria sobre todas las cepas bacterianas probadas, extractos alcohólicos y acuosos mostraron resultados similares. Los extractos de estas dos especies fueron capaces de inhibir las células planctónicas y biofilm microbiano.

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.

The occurrence of diseases and variations from normality is very common in the maxillofacial complex, and this phenomenon is closely associated to peculiar genetic determinants and influenced by genetic isolation. Studies on the distribution of oral diseases and variations from normality in South American natives are generally directed mainly to the study of dental caries in the children and periodontal diseases in the adults, disregarding a wide range of other oral diseases. The aim of this study was to evaluate the distribution of lesions and anatomical variations from normality in eight ethnic groups living in the Umutina Indian Reservation, State of Mato Grosso, Brazil, through physical and oral examinations besides cytological evaluation and assessment of diet and habits, such as tobacco and alcohol consumption. A total of 291 Indians, of both genders, with ages ranging from 1 to 96 years, were examined, being identified 132 variations from normality, evidencing a high occurrence of ankyloglossia, which was present in 108 cases (37.1%), followed by benign migratory glossitis in 5 cases (1.7%); mandibular torus and candidiasis in 3 cases (1.0%). No malignant lesion was identified in the population.

La ocurrencia de enfermedades y variaciones de normalidad son muy comunes en el complejo maxilofacial. Este fenómeno se asocia estrechamente a determinantes genéticos peculiares y son influenciados a través del aislamiento genético. Estudios sobre la distribución de enfermedad oral y variaciones de la normalidad en nativos Sudamericanos son generalmente dirigidos al estudio de la caries dental en niños y enfermedad periodontal en adultos, dejando de lado una amplia gama de otras enfermedades orales. El objetivo de este estudio fue evaluar la distribución de lesiones y las variaciones anatómicas de normalidad en ocho grupos étnicos indígenas pertenecientes a la reserva Umutina, Estado de Mato Grosso, Brasil, a través del examen físico y oral, además de la evaluación citológica y valoración de dieta y hábitos como tabaco y consumo de alcohol. Un total de 291 indígenas de ambos sexos, con edades que van de 1 a 96 años fueron examinados, identificándose 132 variaciones de normalidad, evidenciando una alta ocurrencia de anquiloglosia, la cual se presentó en 108 casos (37,1%), seguido por glositis migratoria benigna en 5 casos (1,7%); torus mandibular y candidiasis en 3 casos (1,0%). Ninguna lesión maligna se identificó en la población.

OBJECTIVES: This study evaluated the resistance to antimicrobials of aerobes and facultative anaerobes isolated from patients wearing complete dentures, patients with gingivitis and periodontitis, and periodontally health subjects. MATERIAL AND METHODS: Three hundred and four isolates were tested. The minimal inhibitory concentrations of the drugs were evaluated through the agar dilution method using Mueller-Hinton agar. RESULTS: The most active antimicrobial drugs were the carbapenems (meropenem and imipenem), and resistance to these drugs was restrict to 1.6-2.3% of the isolates, as well as ciprofloxacin and rifampin. Microbial resistance to ampicillin, amoxicillin/clavulanic acid, cefoxitin, cephalothin, amikacin, chloramphenicol and nalidixic acid was particularly high. In most cases, the resistance to β-lactams was mediated by the production of hydrolytic enzymes, especially in gram-negative enteric rods, while enterococci did not evidence production of these enzymes. The association amoxicillin/clavulanic acid was not effective in 28.3% of the tested isolates. CONCLUSIONS: The results of this investigation confirmed that the oral cavity of patients with periodontitis and gingivitis, and particularly edentulous patients wearing complete dentures could harbor microorganisms with several antimicrobial resistance markers, and these microorganisms are frequently implicated in multiresistant, systemic, oral or nosocomial infections.

Chronic osteomyelitis of maxilla and mandible is rare in industrialized countries and its occurrence in developing countries is associated with trauma and surgery, and its microbial etiology has not been studied thoroughly. The aim of this investigation was to evaluate the microbiota associated with osteomyelitis of mandible or maxilla from some Brazilian patients. After clinical and radiographic evaluation, samples of bone sequestra, purulent secretion, and biopsies of granulomatous tissues from twenty-two patients with chronic osteomyelitis of mandible and maxilla were cultivated and submitted for pathogen detection by using a PCR method. Each patient harbored a single lesion. Bacterial isolation was performed on fastidious anaerobe agar supplemented with hemin, menadione and horse blood for anaerobes; and on tryptic soy agar supplemented with yeast extract and horse blood for facultative bacteria and aerobes. Plates were incubated in anaerobiosis and aerobiosis, at 37ºC for 14 and 3 days, respectively. Bacteria were cultivated from twelve patient samples; and genera Actinomyces, Fusobacterium, Parvimonas, and Staphylococcus were the most frequent. By PCR, bacterial DNA was detected from sixteen patient samples. The results suggest that cases of chronic osteomyelitis of the jaws are usually mixed anaerobic infections, reinforcing the concept that osteomyelitis of the jaws are mainly related to microorganisms from the oral environment, and periapical and periodontal infections may act as predisposing factors.

osteomyelitis of the mandible and maxilla are common in developing countries and their treatment may be long-standing and difficult. Thus, the aim of this study was to discuss the main biological aspects of the chronic osteomyelitis of the jaws of especial interest for dental team. These infections are associated with a complex microbiota composed mainly by anaerobic bacteria, sometimes associated with microorganisms originated from the skin and digestive tract. These data suggest that chronic osteomyelitis of the mandible and maxilla should be treated as anaerobic infections in most cases. In addition, local surgical treatments are relevant in the therapy outcome, associated to the use of antimicrobial agents, and the failure to accomplish them is a major cause of treatment failure.

La osteomielitis maxilar y mandibular son comunes en países en desarrollo y su tratamiento puede ser difícil y de larga duración. Así, el objetivo del presente estudio fue discutir los principales aspectos biológicos de especial interés odontológico de la osteomielitis crónica del maxilar. Estas infecciones están asociadas a una microbiota compleja compuesta principalmente de bacterias anaerobias, algunas veces asociadas a microorganismos oriundos de la piel y del tracto digestivo. Estos datos sugieren que la osteomielitis crónica maxilar y mandibular deben ser tratadas como infecciones anaerobias en la mayoría de los casos. Además, tratamientos quirúrgicos locales son relevantes en el éxito de la terapia, asociados al uso de agentes anti-microbianos, e cuyos resultados no satisfactorios representan una de las principales causas de un tratamiento fallo o no adecuado.

Aggregatibacter actinomycetemcomitans is associated with periodontal disease, especially localized aggressive periodontitis, produces a potent leukotoxin and its distribution is influenced by ethnic characteristics of the population. Objective: Using culture and polymerase chain reaction (PCR) techniques, this study evaluated the occurrence of this microorganism and the distribution of leukotoxic strains isolated from Indians belonging to the Umutima Reservation, Mato Grosso, Brazil. MATERIAL AND METHODS: Forty-eight native Brazilians with gingivitis and 38 with chronic periodontitis, belonging to Umutina, Paresi, Bororo, Bakairi, Kayabi, Irantxe, Nambikwara and Terena ethnicities, were studied. Subgingival, supragingival and saliva samples of each patient were collected and transferred to VMGA III medium and to ultra pure Milli Q water. Bacteria were grown on TSBV agar and incubated in anaerobiosis (90% N2 + 10% CO2) at 37ºC for 72 h. The presence of the ltx promoter was determined by PCR, and a 530 bp deletion in the promoter was evaluated by using specific primers. RESULTS: A. actinomycetemcomitans was isolated from 8.33% of saliva, supragingival and subgingival samples from patients with gingivitis and from 18.42% of saliva and supragingival biofilm, and 26.32% subgingival biofilm from patients with chronic periodontitis. By PCR, the bacterial DNA was detected in 8.33% of saliva, supragingival and subgingival biofilms from patients with gingivitis and from 23.68% of saliva, 28.95% supragingival biofilm and 34.21% subgingival biofilm from patients with periodontitis. All strains were grouped as non-JP2 clones based on the absence of deletion in the leukotoxin promoter. Differences among the microbial and clinical parameters in patients were analyzed by using the Mann-Whitney, Chi-square or Fisher's exact tests. CONCLUSIONS: The present results suggest that A. actinomycetemcomitans can be related to the attachment loss in this population, but the presence of minimally leukotoxic strains, as well as its role in the pathogenesis of the periodontitis in these native Brazilians need to be further investigated.