Fusobacterium nucleatum. ¿un patógeno periodontal promotor de carcinogénesis colorrectal? / Fusobacterium nucleatum. is this periodontal pathogen a promoter of colorectal carcinogenesis?

El Fusobacterium nucleatum es una bacteria anaerobia Gram negativa,es un residente común en el biofi lm oral y se ha encontrado una estrechaasociación entre las fusobacterias y las periodontitis. El Fusobacteriumnucleatum se ha asociado con el cáncer colorrectal, pero la causalidad y el mecanismo subyacente aún no se han establecido. La microbiota intestinal humana tiene un papel reconocido en el cáncer colorrectal. Se ha encontrado que el Fn se adhiere, invade, e induce respuestas inflamatorias oncogénicas que estimulan el crecimiento de las células de cáncer colorrectal a través de un factor de la adhesina FadA.

The anaerobic, Gram-negative bacterial species Fusobacterium nucleatumis common in oral biofi lm and the association between it andperiodontitis is well-established. Fusobacterium nucleatum has beenassociated with colorectal cancer, though causality and the underlyingmechanism have yet to be determined. The role of the human gutmicrobiota in colorectal cancer has been acknowledged. Fusobacteriumnucleatum has been found to adhere to, invade, and induce oncogenicand infl ammatory responses that stimulate the growth of colorectalcancer cells through its unique FadA adhesin.

Periodontal disease induced by porphyromonas gingivalis and fusobacterium nucleatum in Wistarrats / Periodontite induzida pela porphyromonas gingivalis e fusobacterium nucleatum em ratos Wistar

Prior studies have shown that it is necessary to place ligatures around molars to study periodontal destruction in rats. The present research aims to examine a periodontal disease model in which specific pathogen-free Wistar rats are orally exposed to Porphyromonas gingivalis associated with Fusobacterium nucleatum. Periodontitis was induced by specific infection with P. gingivalis and F. nucleatum. Twenty adult male Wistar rats were divided into two groups. The control animals were not infected. The experimental animals were repeatedly infected with Porphyromonas gingivalis and Fusobacterium nucleatum for one week. For the next three weeks, the animals were repeatedly infected with P. gingivalis alone. The distance from the cemento-enamel junction (CEJ) to the alveolar bone crest of the second molar was measured at different sites: buccal-distal (d), buccal-furcation region (f), buccal-mesial (h), and area region. The Mann-Whitney test was applied (p<0.001). The results showed that all values obtained were significantly greater in the infected group. Infected group values for the measures d, f, h, and area were 0.41 mm, 0.46 mm, 0.67mm, and 1.04 mm2, respectively, while in the control group, values for the measures d, f, h, and area were0.19 mm, 0.26 mm, 0.26 mm, 0.88 mm2, respectively. Our study showed that four weeks following infection with Porphyromonas gingivalis and Fusobacterium nucleatum bone loss in Wistar rats could be identified.

Virulence of oral "Fusobacterium nucleatum" from humans and non-human primates in mice

The lethal action in Balb/c mice of 80 oral "Fusobacterium nucleatum" recovered from patients with adult periodontitis, healthy subjects of "Cebus apella" monkeys was studied. Mice were inoculated intraperitoneally with each bacterial inoculum of 5,0E+8 CFU/ml. All the clinical isolates induced weight and coordinated movements loss. Pathological alterations in liver, CNS, heart, and kidney with inflammatory reactions of vascular congestion were observed. Of all the tested "F. nucleatum" isolates, 61.2(per cent) from periodontal patients, 57.1(per cent) from healthy subjects and 60(per cent) from monkeys, were capable of killing the mice in 48h. The clinical isolates were significantly more pathogenic than "F. nucleatum" ATCC 10953 or ATCC 25586. "B. fragilis" ATCC 23745 showed lethality against control mice. Our results suggest that LPS could be involved in lethal action against mice and it may play an important role in producing tissue damage or death of mice.

Bacteriocin-like activity of oral Fusobacterium nucleatum isolated from human and non-human primates

"Fusobacterium nucleatum" is indigenous of the human oral cavity and has been involved in different infectious processes. The production of bacteriocin-like substances may be important in regulation of bacterial microbiota in oral cavity. The ability to produce bacteriocin-like substances by 80 oral "F. nucleatum" isolates obtained from periodontal patients, healthy individuals and "Cebus apella" monkeys, was examinated. 17.5(per cent) of all tested isolates showed auto-antagonism and 78.8(per cent) iso- or hetero-antagonism. No isolate from monkey was capable to produce auto-inhibition. In this study, the antagonistic substances production was variable in all tested isolates. Most of the "F. nucleatum" showed antagonistic activity against tested reference strains. These data suggest a possible participation of these substances on the oral microbial ecology in humans and animals. However, the role of bacteriocins in regulating dental plaque microbiota "in vivo" is discussed

Sintomatologia clínica persistente: devido a infecção endodôntica por Fusobacterium nucleatum / Persistent clinical sintoms: due to endodontic infection by Fusobacterium nucleatum

É reportado um caso clínico onde havia a ocorrência de sintomatologia persistente mesmo após a instrumentação e medicação dos canais radiculares. A análise microbiológica do material coletado do canal revelou a presença de Fusobacterium nucleatum como possível patógeno principal. A remissão dos sintomas apenas ocorreu após antibioticoterapia apropriada

Flora anaerobia predominante en conductos radiculares cerrados con pulpas necróticas / Anaerobic bacteria prevailing in closed root canals with necrotic pulps

En este estudio se hace una descripción de la flora anaerobia (estrictos y facultativos) presente en treinta dientes, de pacientes que ingresaron a la Facultad de Odontología de la Pontificia Universidad Javeriana, previo diagnóstico clínico y radiográfico de necrosis pulpar. Del mismo modo se relacionaron variables como edad del paciente y tipo de sintomatología manifestada (dolor, inflamación y presencia de fístula), con el aislamiento de determinado tipo de microorganismo anaerobio. Los resultados mostraron que de ochenta y nueve cepas aisladas, cincuenta y una correspondían a anaerobios estrictos (57.3 por ciento) y treinta y ocho a anaerobios facultativos (42.7 por ciento). De los estrictos, el Bacteroides melaninogenicus y el Fusobacterium nucleatum fueron los microorganismos predominantes, seguidos por el Peptococo y el Peptoestreptococo. Se encontró que en la mayoría de pacientes con sintomatología aguda se aislaron principalmente anaerobios estrictos, mientras que los pacientes asintomáticos predominaron los facultativos. Finalmente, no se encontró una influencia directa entre la edad del paciente, ni de la presencia o ausencia de fístula, con ningún tipo de microorganismo específico aislado