[Non-pigmented Serratia: utility of hydrolysis of Tween 80 in its identification]. / Serratia no pigmentadas: utilidad de la hidrólisis del Tween 80 en su identificación.

The ability of Serratia sp. to hydrolyze Tween 80 and the usefulness of this test for differentiating it from other Gram negative bacilli was studied, comparing it with the capacity of production of DNAsa by the same strains using the O-Toluidine blue method. The total number of strains assayed was 88. The sensitivity obtained was 83.9% and specificity 91.3%, with a positive predictive value of 83.9% and a negative predictive value of 91.2%. Using this method to differentiate only non-pigmented Serratia from Klebsiella sp. and Enterobacter sp. the sensitivity and specificity obtained was 100%. Concerning the cost, this method proved to be 3.86 times cheaper than the DNAsa one.

[Clinical and microbiological study of adult periodontal disease]. / Estudio clínico y microbiológico de la enfermedad periodontal del adulto.

The aim of this study was to carry out a microbiological evaluation of sites with and without clinical evidence of moderate and severe periodontitis and their correlation with clinical parameters. A total of 52 disease sites and 10 healthy sites were selected according to clinical criteria. The following clinical indexes were measured for all the sites: plaque index, gingival index, blood on probing, depth on probing and insertion level. Samples of subgingival plaque were collected for culture and for differential counts of microbial morphotypes. In disease sites the most frequently isolated were: Prevotella intermedia/nigrescens (65%), Porphyromonas gingivalis (23%), Actinobacillus actinomycetemcomitans (23%), Fusobacterium nucleatum (10%) and Peptostreptococcus sp. (31%). The aerobic gram-positive microflora was predominant in healthy sites. Significant differences were observed in microbial morphotypes between healthy and disease sites: cocci 18.71% and 78.90%, motile rods 46.12% and 16.70%, total spirochetes 26.48% and 2.80%, respectively. The presence of motile rods, spirochetes and P. intermedia/nigrescens were the parameters with most sensitivity to suspect periodontal disease. There were significant differences in the subgingival microflora between healthy and disease sites in patients with moderate and severe periodontitis.

Effect of supragingival plaque control on subgingival microflora and gingivo-periodontal tissues.

The aim of this study was to carry out a short term evaluation of the effect of supragingival plaque control on the subgingival microflora and gingivoperiodontal tissues in patients with moderate and severe periodontitis. A total of 92 sites from 23 patients were studied; patients ranged between 35 and 60 years of age (x 46.4 +/- 1.71). Plaque Index (PI), Gingival Index (GI), Bleeding on Probing (BP), Probing Depth (PD), and Attachment Level (AL) were measured. Subgingival microflora of the same sites was studied by dark field microscopy, and cultures in non-selective and selective media for Actinobacillus actinomycetemcomitans (Aa), Prevotella intermedia/nigrescens (Pi/n), Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn). The patients were included in a supragingival plaque control program which included oral hygiene training and assessment, and professional control of supragingival plaque and calculus. After 28 days, measurement of clinical parameters and the microbiological study were repeated. The sites were divided according to baseline PD values into: Group 1 (5 mm), Group 2 (6 mm) and Group 3 (> or = 7 mm). Results revealed a significant reduction in PI scores, GI scores, PB and PD in groups 2 and 3. No significant difference in AL was observed in any of the three groups. PI scores were found to decrease significantly in group 1, and GI scores, BP and PD tended to decrease. A significant increase in coccoid cells and a significant decrease in motile rods and spirochetes, both small and total, was observed in groups 2 and 3. Group 1 showed a significant decrease in medium and total spirochetes. At the end of the study, a significant decrease in Pi/n was found in all three groups. Significant decreases were found in Pg and Fn in Groups 3 and 2 respectively. Although it holds true that supragingival plaque control reduced a potentially pathogenic subgingival microbiota, this effect was not sufficient to be compatible with healthy gingivoperiodontal tissues.

Serratia no pigmentadas: utilidad de la hidrólisis del tween 80 en su identificación / Identification of Serratia: usefulness of by dialisis of Tween 80

Se estudió la capacidad de Serratia sp. para hidrolizar Tween 80 y la utilidad de esta prueba para diferenciarla de otros bacilos Gram negativos. Se comparó con la capacidad de producción de DNAsa por las mismas cepas utilizando el método de azul de O-Toluidina. Sobre un total de 88 cepas probadas, la sensibilidad obtenida fue de 83,9%, mientras que la especificidad fue del 91,2%, con un valor predictivo positivo de la prueba del 83,9% y un valor predictivo del 91,2%. Utilizando este método con el solo fin de diferenciar Serratia no pigmentada de Klebisiella sp. y Enterobacter sp., la sensibilidad y especificidad fue del 100%. Con respecto al costo, el método de Tween 80 resultó ser 3,86 veces más económico que el de la DNAsa

Estudio clínico y microbiológico de la enfermedad periodontal del adulto / Clinical and microbiological study of adult periodontal disease

The aim of this study was to carry out a microbiological evaluation of sites with and without clinical evidence of moderate and severe periodontitis and their correlation with clinical parameters. A total of 52 disease sites and 10 healthy sites were selected according to clinical criteria. The following clinical indexes were measured for all the sites: plaque index, gingival index, blood on probing, depth on probing and insertion level. Samples of subgingival plaque were collected for culture and for differential counts of microbial morphotypes. In disease sites the most frequently isolated were: Prevotella intermedia/nigrescens (65), Porphyromonas gingivalis (23), Actinobacillus actinomycetemcomitans (23), Fusobacterium nucleatum (10) and Peptostreptococcus sp. (31). The aerobic gram-positive microflora was predominant in healthy sites. Significant differences were observed in microbial morphotypes between healthy and disease sites: cocci 18.71 and 78.90, motile rods 46.12 and 16.70, total spirochetes 26.48 and 2.80, respectively. The presence of motile rods, spirochetes and P. intermedia/nigrescens were the parameters with most sensitivity to suspect periodontal disease. There were significant differences in the subgingival microflora between healthy and disease sites in patients with moderate and severe periodontitis.

Effect of supragingival plaque control on subgingival microflora and gingivo-periodontal tissues

The aim of this study was to carry out a short term evaluation of the effect of supragingival plaque control on the subgingival microflora and gingivoperiodontal tissues in patients with moderate and severe periodontitis. A total of 92 sites from 23 patients were studied; patients ranged between 35 and 60 years of age (x 46.4 +/- 1.71). Plaque Index (PI), Gingival Index (GI), Bleeding on Probing (BP), Probing Depth (PD), and Attachment Level (AL) were measured. Subgingival microflora of the same sites was studied by dark field microscopy, and cultures in non-selective and selective media for Actinobacillus actinomycetemcomitans (Aa), Prevotella intermedia/nigrescens (Pi/n), Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn). The patients were included in a supragingival plaque control program which included oral hygiene training and assessment, and professional control of supragingival plaque and calculus. After 28 days, measurement of clinical parameters and the microbiological study were repeated. The sites were divided according to baseline PD values into: Group 1 (5 mm), Group 2 (6 mm) and Group 3 (> or = 7 mm). Results revealed a significant reduction in PI scores, GI scores, PB and PD in groups 2 and 3. No significant difference in AL was observed in any of the three groups. PI scores were found to decrease significantly in group 1, and GI scores, BP and PD tended to decrease. A significant increase in coccoid cells and a significant decrease in motile rods and spirochetes, both small and total, was observed in groups 2 and 3. Group 1 showed a significant decrease in medium and total spirochetes. At the end of the study, a significant decrease in Pi/n was found in all three groups. Significant decreases were found in Pg and Fn in Groups 3 and 2 respectively. Although it holds true that supragingival plaque control reduced a potentially pathogenic subgingival microbiota, this effect was not sufficient to be compatible with healthy gingivoperiodontal tissues.